Oral contraceptive
Encyclopedia
- "The Pill" redirects here. For other meanings, see Pill (disambiguation). This article is about daily use of COC. For occasional use, see Emergency contraceptionEmergency contraceptionEmergency contraception , or emergency postcoital contraception, refers to birth control measures that, if taken after sexual intercourse, may prevent pregnancy.Forms of EC include:...
.
The combined oral contraceptive pill (COCP), often referred to as the birth-control pill or colloquially as "the Pill", is a birth control method that includes a combination of an estrogen
Estrogen
Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...
(oestrogen) and a progestin
Progestin
A progestin is a synthetic progestogen that has progestinic effects similar to progesterone. The two most common uses of progestins are for hormonal contraception , and to prevent endometrial hyperplasia from unopposed estrogen in hormone replacement therapy...
(progestogen). When taken by mouth every day, these pills inhibit female fertility. They were first approved for contraceptive use in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
in 1960, and are a very popular form of birth control
Birth control
Birth control is an umbrella term for several techniques and methods used to prevent fertilization or to interrupt pregnancy at various stages. Birth control techniques and methods include contraception , contragestion and abortion...
. They are currently used by more than 100 million women worldwide and by almost 12 million women in the United States. Usage varies widely by country, age, education, and marital status: one third of women aged 16–49 in Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
currently use either the combined pill or a progestogen-only "minipill",
compared to only 1% of women in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
.
History
By the 1930s, scientists had isolated and determined the structure of the steroid hormones and found that high doses of androgens, estrogens or progesteroneProgesterone
Progesterone also known as P4 is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy and embryogenesis of humans and other species...
inhibited ovulation
Ovulation
Ovulation is the process in a female's menstrual cycle by which a mature ovarian follicle ruptures and discharges an ovum . Ovulation also occurs in the estrous cycle of other female mammals, which differs in many fundamental ways from the menstrual cycle...
,
but obtaining them from European pharmaceutical companies produced from animal extracts was extraordinarily expensive.
In 1939, Russell Marker
Russell Marker
Russell Earl Marker was an American chemist who invented the octane rating system when he was working at the Ethyl Corporation. Later in his career, he went on to found a steroid industry in Mexico when he successfully made synthetic progesterone from chemical constituents found in Mexican yams...
, a professor of organic chemistry
Organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, composition, reactions, and preparation of carbon-based compounds, hydrocarbons, and their derivatives...
at Pennsylvania State University
Pennsylvania State University
The Pennsylvania State University, commonly referred to as Penn State or PSU, is a public research university with campuses and facilities throughout the state of Pennsylvania, United States. Founded in 1855, the university has a threefold mission of teaching, research, and public service...
, developed a method of synthesizing progesterone
Progesterone
Progesterone also known as P4 is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy and embryogenesis of humans and other species...
from plant steroid sapogenins, initially using sarsapogenin from sarsaparilla
Sarsaparilla
is a perennial trailing vine with prickly stems that is native to Central America. Common names include Sarsaparilla , Honduran Sarsaparilla, and Jamaican Sarsaparilla...
, which proved too expensive. After three years of extensive botanical research, he discovered a much better starting material, the saponin
Saponin
Saponins are a class of chemical compounds, one of many secondary metabolites found in natural sources, with saponins found in particular abundance in various plant species...
from inedible Mexican yams (Dioscorea mexicana
Dioscorea mexicana
Mexican yam or barbasco de placa is a species of yam in the genus Dioscorea. It ranges from the state of Veracruz in Mexico south to Panama. It is notable for its production of diosgenin, which is a precursor for the synthesis of hormones such as progesterone. Russell Marker developed the...
) found in the rain forests of Veracruz
Veracruz
Veracruz, formally Veracruz de Ignacio de la Llave officially Estado Libre y Soberano de Veracruz de Ignacio de la Llave , is one of the 31 states that, along with the Federal District, comprise the 32 federative entities of Mexico. It is divided in 212 municipalities and its capital city is...
near Orizaba
Orizaba
Orizaba is a city and municipality in the Mexican state of Veracruz. It is located 20 km west of its sister city Córdoba, and is adjacent to Río Blanco and Ixtaczoquitlán, on Federal Highways 180 and 190. The city had a 2005 census population of 117,273 and is almost coextensive with its small...
. The saponin could be converted in the lab to its aglycone moiety diosgenin
Diosgenin
Diosgenin, a steroid sapogenin, is the product of hydrolysis by acids, strong bases, or enzymes of saponins, extracted from the tubers of Dioscorea wild yam, such as the Kokoro...
. Unable to interest his research sponsor Parke-Davis
Parke-Davis
Parke-Davis is a subsidiary of the pharmaceutical company Pfizer. Although no longer an independent corporation, it was once America's oldest and largest drug maker, and played an important role in medical history.- History :...
in the commercial potential of synthesizing progesterone from Mexican yams, Marker left Penn State and in 1944 co-founded Syntex
Syntex
Laboratorios Syntex SA was a pharmaceutical company formed in Mexico City in 1944 by Russell Marker to manufacture therapeutic steroids from the Mexican yam....
with two partners in Mexico City
Mexico City
Mexico City is the Federal District , capital of Mexico and seat of the federal powers of the Mexican Union. It is a federal entity within Mexico which is not part of any one of the 31 Mexican states but belongs to the federation as a whole...
before leaving Syntex a year later. Syntex broke the monopoly of European pharmaceutical companies on steroid hormones, reducing the price of progesterone almost 200-fold over the next eight years.
Midway through 20th century, the stage was set for the development of a hormonal contraceptive, but pharmaceutical companies, universities and governments showed no interest in pursuing research.
Studies of progesterone to prevent ovulation
In early 1951, reproductive physiologist Gregory Pincus, a leader in hormone research and co-founder of the Worcester Foundation for Experimental BiologyWorcester Foundation for Experimental Biology
The Worcester Foundation for Biomedical Research was a non-profit biomedical research institute based in Shrewsbury, Massachusetts.-History:...
(WFEB) in Shrewsbury, Massachusetts
Shrewsbury, Massachusetts
-Demographics:As of the census of 2000, there were 31,640 people, 12,366 households, and 8,693 families residing in the town. The population density was . There were 12,696 housing units at an average density of...
, first met American birth control movement founder Margaret Sanger
Margaret Sanger
Margaret Higgins Sanger was an American sex educator, nurse, and birth control activist. Sanger coined the term birth control, opened the first birth control clinic in the United States, and established Planned Parenthood...
at a Manhattan
Manhattan
Manhattan is the oldest and the most densely populated of the five boroughs of New York City. Located primarily on the island of Manhattan at the mouth of the Hudson River, the boundaries of the borough are identical to those of New York County, an original county of the state of New York...
dinner hosted by Abraham Stone, medical director and vice president of Planned Parenthood
Planned Parenthood
Planned Parenthood Federation of America , commonly shortened to Planned Parenthood, is the U.S. affiliate of the International Planned Parenthood Federation and one of its larger members. PPFA is a non-profit organization providing reproductive health and maternal and child health services. The...
(PPFA), who helped Pincus obtain a small grant from PPFA to begin hormonal contraceptive research. Research started on April 25, 1951 with reproductive physiologist Min Chueh Chang
Min Chueh Chang
Dr. Min Chueh Chang , often credited as M.C. Chang, was a Chinese American reproductive biologist. His specific area of study was the fertilisation process in mammalian reproduction...
repeating and extending the 1937 experiments of Makepeace et al. that showed injections of progesterone suppressed ovulation in rabbits. In October 1951, G. D. Searle & Company
G. D. Searle & Company
G.D. Searle & Company or just Searle was a company focusing on life sciences, specifically pharmaceuticals, agriculture, and animal health. It is now part of Pfizer.- History :...
refused Pincus' request to fund his hormonal contraceptive research, but retained him as a consultant and continued to provide chemical compounds to evaluate.
In March 1952, Sanger wrote a brief note mentioning Pincus' research to her longtime friend and supporter, suffragist
Women's suffrage
Women's suffrage or woman suffrage is the right of women to vote and to run for office. The expression is also used for the economic and political reform movement aimed at extending these rights to women and without any restrictions or qualifications such as property ownership, payment of tax, or...
and philanthropist
Philanthropist
A philanthropist is someone who engages in philanthropy; that is, someone who donates his or her time, money, and/or reputation to charitable causes...
Katharine Dexter McCormick, who visited the WFEB and its co-founder and old friend Hudson Hoagland in June 1952 to learn about contraceptive research there. Frustrated when research stalled from PPFA's lack of interest and meager funding, McCormick arranged a meeting at the WFEB on June 6, 1953 with Sanger and Hoagland, where she first met Pincus who committed to dramatically expand and accelerate research with McCormick providing fifty times PPFA's previous funding.
Pincus and McCormick enlisted Harvard
Harvard Medical School
Harvard Medical School is the graduate medical school of Harvard University. It is located in the Longwood Medical Area of the Mission Hill neighborhood of Boston, Massachusetts....
clinical professor of gynecology
Obstetrics and gynaecology
Obstetrics and gynaecology are the two surgical–medical specialties dealing with the female reproductive organs in their pregnant and non-pregnant state, respectively, and as such are often combined to form a single medical specialty and postgraduate training programme...
John Rock
John Rock (American scientist)
John Rock was an American obstetrician and gynecologist. He is best known for the major role he played in the development of the first hormonal contraceptive, colloquially called "the pill".-Early life and career:...
, chief of gynecology at the Free Hospital for Women and an expert in the treatment of infertility
Infertility
Infertility primarily refers to the biological inability of a person to contribute to conception. Infertility may also refer to the state of a woman who is unable to carry a pregnancy to full term...
, to lead clinical research with women. At a scientific conference in 1952, Pincus and Rock, who had known each other for many years, discovered they were using similar approaches to achieve opposite goals. In 1952, Rock induced a three-month anovulatory "pseudo-pregnancy" state in eighty of his infertility patients with continuous gradually increasing oral doses of estrogen
Estrogen
Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...
(diethylstilbestrol
Diethylstilbestrol
Diethylstilbestrol is a synthetic nonsteroidal estrogen that was first synthesized in 1938. Human exposure to DES occurred through diverse sources, such as dietary ingestion from supplemented cattle feed and medical treatment for certain conditions, including breast and prostate cancers...
5–30 mg/day) and progesterone (50–300 mg/day) and within the following four months an encouraging 15% became pregnant.
In 1953, at Pincus' suggestion, Rock induced a three-month anovulatory "pseudo-pregnancy" state in twenty-seven of his infertility patients with an oral 300 mg/day progesterone-only regimen for 20 days from cycle
Menstrual cycle
The menstrual cycle is the scientific term for the physiological changes that can occur in fertile women for the purpose of sexual reproduction. This article focuses on the human menstrual cycle....
days 5–24 followed by pill-free days to produce withdrawal bleeding
Menstrual cycle
The menstrual cycle is the scientific term for the physiological changes that can occur in fertile women for the purpose of sexual reproduction. This article focuses on the human menstrual cycle....
. This produced the same encouraging 15% pregnancy rate during the following four months without the troubling amenorrhea of the previous continuous estrogen and progesterone regimen. But 20% of the women experienced breakthrough bleeding
Breakthrough bleeding
Breakthrough bleeding is an abnormal uterine bleeding that occurs between menstrual periods, especially due to irregular sloughing of the endometrium in women on combined oral contraceptives...
and in the first cycle ovulation was suppressed in only 85% of the women, indicating that even higher and more expensive oral doses of progesterone would be needed to initially consistently suppress ovulation.
Studies of progestins to prevent ovulation
Pincus asked his contacts at pharmaceutical companies to send him chemical compounds with progestogenic activity. Chang screened nearly 200 chemical compounds in animals and found the three most promising were Syntex's norethindrone and Searle's norethynodrelNorethynodrel
Norethynodrel was the progestin used in Enovid, the first oral contraceptive....
and norethandrolone
Norethandrolone
Norethandrolone is an anabolic steroid....
.
Chemists Carl Djerassi
Carl Djerassi
Carl Djerassi is an Austrian-American chemist, novelist, and playwright best known for his contribution to the development of the first oral contraceptive pill . Djerassi is emeritus professor of chemistry at Stanford University.He participated in the invention in 1951, together with Mexican Luis E...
, Luis Miramontes
Luis E. Miramontes
Luis Ernesto Miramontes Cárdenas , was a Mexican chemist known as the co-inventor of the progestin used in one of the first two oral contraceptives....
, and George Rosenkranz
George Rosenkranz
George Rosenkranz is a Mexican scientist in steroid research and a professional bridge player. He was born in Hungary, educated in Switzerland and lived in Mexico for 66 years...
at Syntex in Mexico City had synthesized the first orally highly active progestin norethindrone in 1951. Chemist Frank B. Colton
Frank B. Colton
Frank Benjamin Colton , American chemist who first synthesized norethynodrel, the progestin used in Enovid, the first oral contraceptive, at G. D. Searle & Company in Skokie, Illinois in 1952....
at Searle in Skokie, Illinois
Skokie, Illinois
Skokie is a village in Cook County, Illinois, United States. Its name comes from a Native American word for "fire". A Chicago suburb, for many years Skokie promoted itself as "The World's Largest Village". Its population, per the 2000 census, was 63,348...
had synthesized the orally highly active progestins norethynodrel (an isomer of norethindrone) in 1952 and norethandrolone in 1953.
In December 1954, Rock began the first studies of the ovulation-suppressing potential of 5–50 mg doses of the three oral progestins for three months (for 21 days per cycle—days 5–25 followed by pill-free days to produce withdrawal bleeding) in fifty of his infertility patients in Brookline, Massachusetts
Brookline, Massachusetts
Brookline is a town in Norfolk County, Massachusetts, United States, which borders on the cities of Boston and Newton. As of the 2010 census, the population of the town was 58,732.-Etymology:...
. Norethindrone or norethynodrel 5 mg doses and all doses of norethandrolone suppressed ovulation but caused breakthrough bleeding, but 10 mg and higher doses of norethindrone or norethynodrel suppressed ovulation without breakthrough bleeding and led to a 14% pregnancy rate in the following five months. Pincus and Rock selected Searle's norethynodrel for the first contraceptive trials in women, citing its total lack of androgenicity versus Syntex's norethindrone's very slight androgenicity in animal tests.
Development of an effective combined oral contraceptive
Norethynodrel (and norethindrone) were subsequently discovered to be contaminated with a small percentage of the estrogen mestranolMestranol
Mestranol is the 3-methyl ether of ethinylestradiol. It was the estrogen used in many of the first oral contraceptives.It is a biologically inactive prodrug of ethinylestradiol to which it is demethylated in the liver with a conversion efficiency of 70% ....
(an intermediate in their synthesis), with the norethynodrel in Rock's 1954-5 study containing 4-7% mestranol. When further purifying norethynodrel to contain less than 1% mestranol led to breakthrough bleeding, it was decided to intentionally incorporate 2.2% mestranol, a percentage that was not associated with breakthrough bleeding, in the first contraceptive trials in women in 1956. The norethynodrel and mestranol combination was given the proprietary name Enovid
Enovid
Enovid or Enavid was the first combined oral contraceptive pill . Developed by G. D. Searle & Company, it was first made available in the U.S. in 1957. Initially Enovid was marketed only for the treatment of menstrual disorders. On May 9, 1960 the U.S...
.
The first contraceptive trial of Enovid led by Edris Rice-Wray began in April 1956 in Río Piedras, Puerto Rico
Río Piedras, Puerto Rico
Río Piedras is a district of San Juan, Puerto Rico. Founded in 1714, it has been the home of the University of Puerto Rico's main campus since 1903, earning the town the popular name of Ciudad Universitaria...
. A second contraceptive trial of Enovid (and norethindrone) led by Edward T. Tyler began in June 1956 in Los Angeles
Los Ángeles
Los Ángeles is the capital of the province of Biobío, in the commune of the same name, in Region VIII , in the center-south of Chile. It is located between the Laja and Biobío rivers. The population is 123,445 inhabitants...
. On January 23, 1957, Searle held a symposium reviewing gynecologic and contraceptive research on Enovid through 1956 and concluded Enovids estrogen content could be reduced by 33% to lower the incidence of estrogenic gastrointestinal side effects without significantly increasing the incidence of breakthrough bleeding.
United States
On June 10, 1957, the Food and Drug AdministrationFood and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
(FDA) approved Enovid 10 mg (9.85 mg norethynodrel and 150 µg mestranol) for menstrual disorders based on data from its use by more than 600 women. Numerous additional contraceptive trials showed Enovid at 10, 5, and 2.5 mg doses to be highly effective. On July 23, 1959, Searle filed a supplemental application to add contraception as an approved indication for 10, 5, and 2.5 mg doses of Enovid. The FDA refused to consider the application until Searle agreed to withdraw the lower dosage forms from the application. On May 9, 1960, the FDA announced it would approve Enovid 10 mg for contraceptive use, which it did on June 23, 1960, by which time Enovid 10 mg had been in general use for three years during which time, by conservative estimate, at least half a million women had used it.
Although FDA-approved for contraceptive use, Searle never marketed Enovid 10 mg as a contraceptive. Eight months later, on February 15, 1961, the FDA approved Enovid 5 mg for contraceptive use. In July 1961, Searle finally began marketing Enovid 5 mg (5 mg norethynodrel and 75 µg mestranol) to physicians as a contraceptive.
Although the FDA approved the first oral contraceptive in 1960, contraceptives were not available to married women in all states until Griswold v. Connecticut
Griswold v. Connecticut
Griswold v. Connecticut, , was a landmark case in which the Supreme Court of the United States ruled that the Constitution protected a right to privacy. The case involved a Connecticut law that prohibited the use of contraceptives...
in 1965 and were not available to unmarried women in all states until Eisenstadt v. Baird
Eisenstadt v. Baird
Eisenstadt v. Baird, , was an important United States Supreme Court case that established the right of unmarried people to possess contraception on the same basis as married couples and, by implication, the right of unmarried couples to engage in potentially nonprocreative sexual intercourse .The...
in 1972.
The first published case report of a blood clot and pulmonary embolism
Pulmonary embolism
Pulmonary embolism is a blockage of the main artery of the lung or one of its branches by a substance that has travelled from elsewhere in the body through the bloodstream . Usually this is due to embolism of a thrombus from the deep veins in the legs, a process termed venous thromboembolism...
in a woman using Enavid (Enovid 10 mg in the U.S.) at a dose of 20 mg/day did not appear until November 1961, four years after its approval, by which time it had been used by over one million women. It would take almost a decade of epidemiological studies to conclusively establish an increased risk of venous thrombosis
Venous thrombosis
A venous thrombosis is a blood clot that forms within a vein. A venous thrombosis is a blood clot that forms within a vein. A venous thrombosis is a blood clot that forms within a vein. (Thrombosis is a medical term for blood clotting (Haemostasis) occurring in the wrong place, i.e...
in oral contraceptive users and an increased risk of stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
and myocardial infarction
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
in oral contraceptive users who smoke
Tobacco smoking
Tobacco smoking is the practice where tobacco is burned and the resulting smoke is inhaled. The practice may have begun as early as 5000–3000 BCE. Tobacco was introduced to Eurasia in the late 16th century where it followed common trade routes...
or have high blood pressure or other cardiovascular or cerebrovascular risk factors. These risks of oral contraceptives were dramatized in the 1969 book The Doctors' Case Against the Pill by feminist journalist Barbara Seaman
Barbara Seaman
Barbara Seaman was an American author, activist, and journalist, and a principal founder of the women's health feminism movement.-Early years:Seaman, whose parents, Henry J...
who helped arrange the 1970 Nelson Pill Hearings
Nelson Pill Hearings
In 1970, Barbara Seaman brought the dangers of combined oral contraceptive pill use to the attention of Senator Gaylord Nelson with her book The Doctors Case Against the Pill...
called by Senator Gaylord Nelson
Gaylord Nelson
Gaylord Anton Nelson was an American politician from Wisconsin who served as a United States Senator and governor. A Democrat, he was the principal founder of Earth Day.-Public service and leadership:...
. The hearings were conducted by Senators who were all men and the witnesses in the first round of hearings were all men, leading Alice Wolfson
Alice Wolfson
Alice Wolfson, a Barnard graduate and former Fulbright Scholar, is a veteran political activist in women's reproductive health issues, a lawyer, and a co-founder of the National Women's Health Network....
and other feminists to protest the hearings and generate media attention. Their work led to mandating the inclusion of patient package inserts with oral contraceptives to explain their possible side effects and risks to help facilitate informed consent
Informed consent
Informed consent is a phrase often used in law to indicate that the consent a person gives meets certain minimum standards. As a literal matter, in the absence of fraud, it is redundant. An informed consent can be said to have been given based upon a clear appreciation and understanding of the...
. Today's standard dose oral contraceptives contain an estrogen dose that is one third lower than the first marketed oral contraceptive and contain lower doses of different, more potent progestins in a variety of formulations. It has become easy to obtain a prescription from a doctor; and typical method cost is $15 to $50 per month.
Many economists argue that the availability of the Birth Control Pill led to an increase in women in the labor force. Since the pill allowed women to have a sexual relationship while pursuing a career, it is given credit as one of the factors in the quiet revolution.
Canada
The Combined Oral Contraceptive, as well as many other methods of birth control, was legalized in Canada in 1969.Australia
The first oral contraceptive introduced outside the United States was ScheringSchering
Schering AG was a research-centered German pharmaceutical company. It was founded in 1851 by Ernst Christian Friedrich Schering and merged with Bayer's pharma sector in December 2006. The company's headquarters was in Berlin-Wedding, Germany...
's Anovlar (norethindrone acetate
Norethindrone acetate
Norethisterone acetate or norethindrone acetate is a progestin used in contraception. It is the acetate ester of norethisterone....
4 mg + ethinyl estradiol
Ethinylestradiol
Ethynylestradiol , also ethynyl estradiol , is a derivative of estradiol. Ethynyl estradiol is an orally bio-active estrogen used in almost all modern formulations of combined oral contraceptive pills...
50 µg) on January 1, 1961 in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
.
Germany
The first oral contraceptive introduced in EuropeEurope
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
was Schering's Anovlar on June 1, 1961 in West Germany
West Germany
West Germany is the common English, but not official, name for the Federal Republic of Germany or FRG in the period between its creation in May 1949 to German reunification on 3 October 1990....
. The lower hormonal dose, still in use, was studied by the Belgian Gynaecologist Ferdinand Peeters. Later, Gergory Pincus changed his Enovid, in July 1961, to the same dose.
United Kingdom
Before the mid-1960s, the United Kingdom did not require pre-marketing approval of drugs. The British Family Planning AssociationFamily Planning Association
FPA is a UK registered charity working to enable people to make informed choices about sex and to enjoy sexual health. It is the national affiliate for the International Planned Parenthood Federation in the United Kingdom. It celebrated its 80th anniversary in 2010...
(FPA) through its clinics was then the primary provider of family planning services in Britain and provided only contraceptives that were on its Approved List of Contraceptives (established in 1934). In 1957, Searle began marketing Enavid (Enovid 10 mg in the U.S.) for menstrual disorders. Also in 1957, the FPA established a Council for the Investigation of Fertility Control (CIFC) to test and monitor oral contraceptives which began animal testing of oral contraceptives and in 1960 and 1961 began three large clinical trials in Birmingham
Birmingham
Birmingham is a city and metropolitan borough in the West Midlands of England. It is the most populous British city outside the capital London, with a population of 1,036,900 , and lies at the heart of the West Midlands conurbation, the second most populous urban area in the United Kingdom with a...
, Slough
Slough
Slough is a borough and unitary authority within the ceremonial county of Royal Berkshire, England. The town straddles the A4 Bath Road and the Great Western Main Line, west of central London...
, and London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
.
In March 1960, the Birmingham FPA began trials of norethynodrel 2.5 mg + mestranol 50 µg, but a high pregnancy rate initially occurred when the pills accidentally contained only 36 µg of mestranol—the trials were continued with norethynodrel 5 mg + mestranol 75 µg (Conovid in Britain, Enovid 5 mg in the U.S.).
In August 1960, the Slough FPA began trials of norethynodrel 2.5 mg + mestranol 100 µg (Conovid-E in Britain, Enovid-E in the U.S.).
In May 1961, the London FPA began trials of Schering's Anovlar.
In October 1961, at the recommendation of the Medical Advisory Council of its CIFC, the FPA added Searle's Conovid to its Approved List of Contraceptives.
On December 4, 1961, Enoch Powell
Enoch Powell
John Enoch Powell, MBE was a British politician, classical scholar, poet, writer, and soldier. He served as a Conservative Party MP and Minister of Health . He attained most prominence in 1968, when he made the controversial Rivers of Blood speech in opposition to mass immigration from...
, then Minister of Health, announced that the oral contraceptive pill Conovid could be prescribed through the NHS
National Health Service
The National Health Service is the shared name of three of the four publicly funded healthcare systems in the United Kingdom. They provide a comprehensive range of health services, the vast majority of which are free at the point of use to residents of the United Kingdom...
at a subsidized price of 2s
Shilling
The shilling is a unit of currency used in some current and former British Commonwealth countries. The word shilling comes from scilling, an accounting term that dates back to Anglo-Saxon times where it was deemed to be the value of a cow in Kent or a sheep elsewhere. The word is thought to derive...
per month.
In 1962, Schering's Anovlar and Searle's Conovid-E were added to the FPA's Approved List of Contraceptives.
The contraceptive pill is currently available free of charge on the NHS - prescribed contraceptives are exempt from the NHS prescription charge.
France
On December 28, 1967, the Neuwirth Law legalized contraception in France, including the pill. The pill is the most popular form of contraception in France, especially among young women. It accounts for 60% of the birth control used in France. The abortion rate has remained stable since the introduction of the pill.Italy
Although prescription drugs containing the same chemicals used in COCP had been approved for sale in Italy since 1965 for the purpose of "regularizing the menstrual cycle", the sale of drugs explicitly labeled as "contraceptives" remained illegal until 1971, when a ruling of the Constitutional Court struck down a provision of the Criminal Code (enacted in 1938 by the FascistFascism
Fascism is a radical authoritarian nationalist political ideology. Fascists seek to rejuvenate their nation based on commitment to the national community as an organic entity, in which individuals are bound together in national identity by suprapersonal connections of ancestry, culture, and blood...
regime) that defined birth control as a "crime against human race". However, due to the staunch opposition of the Catholic Church to contraceptive methods (underlined in 1968 by Pope Paul VI
Pope Paul VI
Paul VI , born Giovanni Battista Enrico Antonio Maria Montini , reigned as Pope of the Catholic Church from 21 June 1963 until his death on 6 August 1978. Succeeding Pope John XXIII, who had convened the Second Vatican Council, he decided to continue it...
in his encyclical "Humanae Vitae
Humanae Vitae
Humanae Vitae is an encyclical written by Pope Paul VI and issued on 25 July 1968. Subtitled On the Regulation of Birth, it re-affirms the traditional teaching of the Catholic Church regarding married love, responsible parenthood, and the continuing proscription of most forms of birth...
") and negative propaganda by conservative media, Italy lags behind all other Western European nations in COCP prescriptions. Recent statistical data reveals that less than 20% of Italian women aged between 15 to 55 make regular use of any kind of contraceptive.
Japan
In JapanJapan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, lobbying from the Japan Medical Association prevented the Pill from being approved for nearly 40 years. Two main objections raised by the association were safety concerns over long-term use of the Pill, and concerns that the Pill use would lead to diminished use of condoms and thereby potentially increase sexually transmitted infection (STI) rates. As of 2004, condoms accounted for 80% of birth control use in Japan, and this may explain Japan's comparatively low rates of AIDS.
The Pill was approved for use in June 1999. According to estimates, only 1.3 percent of 28 million Japanese females use the Pill, compared with 15.6 percent in the United States. The Pill prescription guidelines the government endorsed require Pill users to visit a doctor every three months for pelvic examinations and undergo tests for sexually transmitted diseases and uterine cancer. In the United States and Europe, in contrast, an annual or bi-annual clinic visit is standard for Pill users. However, as far back as 2007, many Japanese OBGYNs now only require a yearly visit for pill users, with the tri-annual visits only recommended to those who are older or at increased risk of side effects.
Use and packaging
Placebo
A placebo is a simulated or otherwise medically ineffectual treatment for a disease or other medical condition intended to deceive the recipient...
. A woman on the pill will have a withdrawal bleed sometime during the placebo week, and is still protected from pregnancy during this week. There are also two newer combination birth control pills (Yaz 28 and Loestrin 24 Fe) that have 24 days of active hormone pills, followed by 4 days of placebo.
Placebo pills
The placebo pills allow the user to take a pill every day; remaining in the daily habit even during the week without hormones. Placebo pills may contain an ironIron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
supplement, as iron requirements increase during menstruation.
Failure to take pills during the placebo week does not impact the effectiveness of the pill, provided that daily ingestion of active pills is resumed at the end of the week.
The withdrawal bleeding that occurs during the break from active pills was thought to be comforting, as a physical confirmation of not being pregnant. The 28-day pill package also simulates the average menstrual cycle
Menstrual cycle
The menstrual cycle is the scientific term for the physiological changes that can occur in fertile women for the purpose of sexual reproduction. This article focuses on the human menstrual cycle....
, though the hormonal events during a pill cycle are significantly different from those of a normal ovulatory menstrual cycle. The withdrawal bleeding is also predictable; as a woman goes longer periods of time taking only active pills, unexpected breakthrough bleeding becomes a more common side effect.
Less frequent placebos
If the pill formulation is monophasic, it is possible to skip withdrawal bleeding and still remain protected against conception by skipping the placebo pills and starting directly with the next packet. Attempting this with bi- or tri-phasic pill formulations carries an increased risk of breakthrough bleedingBreakthrough bleeding
Breakthrough bleeding is an abnormal uterine bleeding that occurs between menstrual periods, especially due to irregular sloughing of the endometrium in women on combined oral contraceptives...
and may be undesirable. It will not, however, increase the risk of getting pregnant.
Starting in 2003, women have also been able to use a three-month version of the Pill. Similar to the effect of using a constant-dosage formulation and skipping the placebo weeks for three months, Seasonale
Seasonale
Extended cycle combined oral contraceptive pills are COCPs packaged to reduce or eliminate the withdrawal bleeding that occurs once every 28 days in traditionally packaged COCPs...
gives the benefit of less frequent periods, at the potential drawback of breakthrough bleeding. Seasonique is another version in which the placebo week every three months is replaced with a week of low-dose estrogen.
A version of the combined pill has also been packaged to completely eliminate placebo pills and withdrawal bleeds. Marketed as Anya or Lybrel, studies have shown that after seven months, 71% of users no longer had any breakthrough bleeding, the most common side effect of going longer periods of time without breaks from active pills.
Effectiveness
The effectiveness of COCPs, as of most forms of contraceptionBirth control
Birth control is an umbrella term for several techniques and methods used to prevent fertilization or to interrupt pregnancy at various stages. Birth control techniques and methods include contraception , contragestion and abortion...
, can be assessed in two ways. Perfect use or method effectiveness rates only include people who take the pills consistently and correctly. Actual use, or typical use effectiveness rates are of all COCP users, including those who take the pills incorrectly, inconsistently, or both. Rates are generally presented for the first year of use. Most commonly the Pearl Index
Pearl Index
The Pearl Index, also called the Pearl rate, is the most common technique used in clinical trials for reporting the effectiveness of a birth control method.-Calculation and usage:...
is used to calculate effectiveness rates, but some studies use decrement table
Decrement table
Decrement tables, also called life table methods, are used to calculate the probability of certain events.-Birth control:Life table methods are often used to study birth control effectiveness...
s.
The typical use pregnancy rate among COCP users varies depending on the population being studied, ranging from 2-8% per year. The perfect use pregnancy rate of COCPs is 0.3% per year.
Several factors account for typical use effectiveness being lower than perfect use effectiveness:
- mistakes on the part of those providing instructions on how to use the method
- mistakes on the part of the user
- conscious user non-compliance with instructions.
For instance, someone using oral forms of hormonal birth control might be given incorrect information by a health care provider as to the frequency of intake, or by mistake not take the pill one day, or simply not go to the pharmacy on time to renew the prescription.
COCPs provide effective contraception from the very first pill if started within five days of the beginning of the menstrual cycle
Menstrual cycle
The menstrual cycle is the scientific term for the physiological changes that can occur in fertile women for the purpose of sexual reproduction. This article focuses on the human menstrual cycle....
(within five days of the first day of menstruation
Menstruation
Menstruation is the shedding of the uterine lining . It occurs on a regular basis in sexually reproductive-age females of certain mammal species. This article focuses on human menstruation.-Overview:...
). If started at any other time in the menstrual cycle, COCPs provide effective contraception only after 7 consecutive days use of active pills, so a backup method of contraception must be used until active pills have been taken for 7 consecutive days. COCPs should be taken at approximately the same time every day.
Contraceptive efficacy may be impaired by: 1) missing more than one active pill in a packet, 2) delay in starting the next packet of active pills (i.e., extending the pill-free, inactive or placebo pill period beyond 7 days), 3) intestinal
Intestine
In human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...
malabsorption
Malabsorption
Malabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal tract.Impairment can be of single or multiple nutrients depending on the abnormality...
of active pills due to vomiting
Vomiting
Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...
or diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
, 4) drug interactions with active pills that decrease contraceptive estrogen or progestogen levels.
Little research on the physiological effects of alcohol consumption during puberty has focused on human females. However, one study found that estrogen levels were depressed among adolescent girls ages 12 to 18 for as long as 2 weeks after drinking moderately (Block et al. 1993). Mild–to–moderate alcohol use has numerous negative consequences for female reproductive function.
Mechanism of action
Combined oral contraceptive pills were developed to prevent ovulationOvulation
Ovulation is the process in a female's menstrual cycle by which a mature ovarian follicle ruptures and discharges an ovum . Ovulation also occurs in the estrous cycle of other female mammals, which differs in many fundamental ways from the menstrual cycle...
by suppressing the release of gonadotropin
Gonadotropin
Gonadotropins are protein hormones secreted by gonadotrope cells of the pituitary gland of vertebrates. This is a family of proteins, which include the mammalian hormones follitropin , lutropin , placental chorionic gonadotropins hCG and eCG and chorionic gonadotropin , as well as at least two...
s. Combined hormonal contraceptives, including COCPs, inhibit follicular development
Follicular phase
The follicular phase is the phase of the estrous cycle, during which follicles in the ovary mature. It ends with ovulation. The main hormone controlling this stage is estradiol....
and prevent ovulation as their primary mechanism of action.
Progestagen negative feedback
Negative feedback
Negative feedback occurs when the output of a system acts to oppose changes to the input of the system, with the result that the changes are attenuated. If the overall feedback of the system is negative, then the system will tend to be stable.- Overview :...
decreases the pulse frequency of gonadotropin-releasing hormone
Gonadotropin-releasing hormone
Gonadotropin-releasing hormone , also known as Luteinizing-hormone-releasing hormone and luliberin, is a tropic peptide hormone responsible for the release of follicle-stimulating hormone and luteinizing hormone from the anterior pituitary. GnRH is synthesized and released from neurons within...
(GnRH) release by the hypothalamus
Hypothalamus
The Hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions...
, which decreases the release of follicle-stimulating hormone
Follicle-stimulating hormone
Follicle-stimulating hormone is a hormone found in humans and other animals. It is synthesized and secreted by gonadotrophs of the anterior pituitary gland. FSH regulates the development, growth, pubertal maturation, and reproductive processes of the body. FSH and Luteinizing hormone act...
(FSH) and greatly decreases the release of luteinizing hormone
Luteinizing hormone
Luteinizing hormone is a hormone produced by the anterior pituitary gland. In females, an acute rise of LH called the LH surge triggers ovulation and development of the corpus luteum. In males, where LH had also been called interstitial cell-stimulating hormone , it stimulates Leydig cell...
(LH) by the anterior pituitary
Anterior pituitary
A major organ of the endocrine system, the anterior pituitary, also called the adenohypophysis, is the glandular, anterior lobe of the pituitary gland...
. Decreased levels of FSH inhibit follicular development, preventing an increase in estradiol
Estradiol
Estradiol is a sex hormone. Estradiol is abbreviated E2 as it has 2 hydroxyl groups in its molecular structure. Estrone has 1 and estriol has 3 . Estradiol is about 10 times as potent as estrone and about 80 times as potent as estriol in its estrogenic effect...
levels. Progestagen negative feedback and the lack of estrogen positive feedback
Positive feedback
Positive feedback is a process in which the effects of a small disturbance on a system include an increase in the magnitude of the perturbation. That is, A produces more of B which in turn produces more of A. In contrast, a system that responds to a perturbation in a way that reduces its effect is...
on LH release prevent a mid-cycle
Menstrual cycle
The menstrual cycle is the scientific term for the physiological changes that can occur in fertile women for the purpose of sexual reproduction. This article focuses on the human menstrual cycle....
LH surge. Inhibition of follicular development and the absence of a LH surge prevent ovulation.
Estrogen was originally included in oral contraceptives for better cycle control (to stabilize the endometrium and thereby reduce the incidence of breakthrough bleeding), but was also found to inhibit follicular development and help prevent ovulation. Estrogen negative feedback on the anterior pituitary greatly decreases the release of FSH, which inhibits follicular development and helps prevent ovulation.
A secondary mechanism of action of all progestagen-containing contraceptives is inhibition of sperm
Spermatozoon
A spermatozoon is a motile sperm cell, or moving form of the haploid cell that is the male gamete. A spermatozoon joins an ovum to form a zygote...
penetration through the cervix
Cervix
The cervix is the lower, narrow portion of the uterus where it joins with the top end of the vagina. It is cylindrical or conical in shape and protrudes through the upper anterior vaginal wall...
into the upper genital tract
Female reproductive system (human)
The female reproductive system contains two main parts: the uterus, which hosts the developing fetus, produces vaginal and uterine secretions, and passes the anatomically male person's sperm through to the fallopian tubes; and the ovaries, which produce the anatomically female person's egg cells...
(uterus
Uterus
The uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...
and fallopian tube
Fallopian tube
The Fallopian tubes, also known as oviducts, uterine tubes, and salpinges are two very fine tubes lined with ciliated epithelia, leading from the ovaries of female mammals into the uterus, via the utero-tubal junction...
s) by decreasing the amount of and increasing the viscosity
Viscosity
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...
of the cervical mucus.
Other possible secondary mechanisms may exist. For instance, the brochure for Bayer's YAZ mentions changes in the endometrial
Endometrium
-Function:The endometrium is the innermost glandular layer and functions as a lining for the uterus, preventing adhesions between the opposed walls of the myometrium, thereby maintaining the patency of the uterine cavity. During the menstrual cycle or estrous cycle, the endometrium grows to a...
effects that reduce the likelihood of implantation of an embryo in the uterus. Some pro-life
Pro-life
Opposition to the legalization of abortion is centered around the pro-life, or anti-abortion, movement, a social and political movement opposing elective abortion on moral grounds and supporting its legal prohibition or restriction...
groups consider such a mechanism to be abortifacient
Abortifacient
An abortifacient is a substance that induces abortion. Abortifacients for animals that have mated undesirably are known as mismating shots....
, and the existence of postfertilization mechanisms is a controversial topic. Some scientists point out that the possibility of fertilization during COCP use is very small. From this, they conclude that endometrial changes are unlikely to play an important role, if any, in the observed effectiveness of COCPs. Others make more complex arguments against the existence of these mechanisms, while yet other scientists argue the existing data supports such mechanisms. The controversy is currently unresolved.
Drug interactions
Some drugMedication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
s reduce the effect of the Pill and can cause breakthrough bleeding
Breakthrough bleeding
Breakthrough bleeding is an abnormal uterine bleeding that occurs between menstrual periods, especially due to irregular sloughing of the endometrium in women on combined oral contraceptives...
, or increased chance of pregnancy. These include drugs such as rifampicin
Rifampicin
Rifampicin or rifampin is a bactericidal antibiotic drug of the rifamycin group. It is a semisynthetic compound derived from Amycolatopsis rifamycinica ...
, barbiturate
Barbiturate
Barbiturates are drugs that act as central nervous system depressants, and can therefore produce a wide spectrum of effects, from mild sedation to total anesthesia. They are also effective as anxiolytics, as hypnotics, and as anticonvulsants...
s, phenytoin
Phenytoin
Phenytoin sodium is a commonly used antiepileptic. Phenytoin acts to suppress the abnormal brain activity seen in seizure by reducing electrical conductance among brain cells by stabilizing the inactive state of voltage-gated sodium channels...
and carbamazepine
Carbamazepine
Carbamazepine is an anticonvulsant and mood-stabilizing drug used primarily in the treatment of epilepsy and bipolar disorder, as well as trigeminal neuralgia...
. In addition cautions are given about broad spectrum antibiotics, such as ampicillin
Ampicillin
Ampicillin is a beta-lactam antibiotic that has been used extensively to treat bacterial infections since 1961. Until the introduction of ampicillin by the British company Beecham, penicillin therapies had only been effective against Gram-positive organisms such as staphylococci and streptococci...
and doxycycline
Doxycycline
Doxycycline INN is a member of the tetracycline antibiotics group, and is commonly used to treat a variety of infections. Doxycycline is a semisynthetic tetracycline invented and clinically developed in the early 1960s by Pfizer Inc. and marketed under the brand name Vibramycin. Vibramycin...
, which may cause problems "by impairing the bacterial flora responsible for recycling ethinylestradiol
Ethinylestradiol
Ethynylestradiol , also ethynyl estradiol , is a derivative of estradiol. Ethynyl estradiol is an orally bio-active estrogen used in almost all modern formulations of combined oral contraceptive pills...
from the large bowel" (BNF
British National Formulary
The British National Formulary is a medical and pharmaceutical reference book that contains a wide spectrum of information and advice on prescribing and pharmacology, along with specific facts and details about all medicines available on the National Health Service , including indication,...
2003).
The traditional medicinal herb St John's Wort
St John's wort
St John's wort is the plant species Hypericum perforatum, and is also known as Tipton's Weed, Chase-devil, or Klamath weed....
has also been implicated due to its upregulation of the P450 system in the liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
.
Little research on the physiological effects of alcohol consumption during puberty has focused on human females. However, one study found that estrogen levels were depressed among adolescent girls ages 12 to 18 for as long as 2 weeks after drinking moderately (Block et al. 1993). Mild–to–moderate alcohol use has numerous negative consequences for female reproductive function.
Side effects
Different sources note different incidences of side effects. The most common side effect is breakthrough bleedingBreakthrough bleeding
Breakthrough bleeding is an abnormal uterine bleeding that occurs between menstrual periods, especially due to irregular sloughing of the endometrium in women on combined oral contraceptives...
. A University of New Mexico
University of New Mexico
The University of New Mexico at Albuquerque is a public research university located in Albuquerque, New Mexico, in the United States. It is the state's flagship research institution...
Student Health Center webpage says the majority (about 60%) of women report no side effects at all, and the vast majority of those who do, have only minor effects.
A 1992 French review article said that as many as 50% of new first-time users discontinue the birth control pill before the end of the first year because of the annoyance of side effects such as breakthrough bleeding and amenorrhea.
On the other hand, the pills improve conditions such as pelvic inflammatory disease, dysmenorrhea, premenstrual syndrome, and acne. And they reduce symptoms of endometriosis and polycystic ovary syndrome, and decrease the risk of anemia.
It is generally accepted by medical authorities that the health risks of oral contraceptives are lower than those from pregnancy and birth, and "the health benefits of any method of contraception are far greater than any risks from the method". Some organizations have argued that comparing a contraceptive method to no method (pregnancy) is not relevant—instead, the comparison of safety should be among available methods of contraception.
Venous thromboembolism
Combined oral contraceptives increase the risk of venous thromboembolism (including deep vein thrombosisDeep vein thrombosis
Deep vein thrombosis is the formation of a blood clot in a deep vein. Deep vein thrombosis commonly affects the leg veins or the deep veins of the pelvis. Occasionally the veins of the arm are affected...
(DVT) and pulmonary embolism
Pulmonary embolism
Pulmonary embolism is a blockage of the main artery of the lung or one of its branches by a substance that has travelled from elsewhere in the body through the bloodstream . Usually this is due to embolism of a thrombus from the deep veins in the legs, a process termed venous thromboembolism...
(PE)). On average the risk of fatal PE is 1 per 100,000 women.
The risk of thromboembolism varies with different preparations; with second-generation pills (with an estrogen content less than 50μg), the risk of thromboembolism is small, with an incidence of approximately 15 per 100,000 users per year, compared with 5 per 100,000 per year among non-pregnant individuals not taking the pill, and 60 per 100,000 pregnancies. In individuals using preparations containing third-generation progestogens (desogestrel
Desogestrel
Desogestrel is a molecule used in hormonal contraceptives.-Benefits:Third-generation oral contraceptives are suitable for use in patients with diabetes or lipid disorders because they have minimal impact on blood glucose levels and the lipid profile...
or gestodene
Gestodene
Gestodene is a progestogen hormonal contraceptive. Products containing gestodene include:*Melodene-15, Mirelle, and Minesse which contain 15 mcg of ethinylestradiol and 60 mcg of gestodene;...
), the incidence of thromboembolism is approximately 25 per 100,000 users per year. Also, the risk is greatest in subgroups with additional factors, such as smoking (which increases risk substantially) and long-continued use of the pill, especially in women over 35 years of age.
COC confer a risk of first ischemic stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
, and current use significantly increases the risk of cardio-vascular disease among those at high risk.
Cancer
A systematic reviewSystematic review
A systematic review is a literature review focused on a research question that tries to identify, appraise, select and synthesize all high quality research evidence relevant to that question. Systematic reviews of high-quality randomized controlled trials are crucial to evidence-based medicine...
in 2010, which looked at several previous studies of multiple types of cancer, did not support an increased cancer risk in users of combined oral contraceptive pill.
COC decrease the risk of ovarian cancer, endometrial cancer, and colorectal cancer.
Monograph 91 of The International Agency for Research on Cancer
International Agency for Research on Cancer
The International Agency for Research on Cancer is an intergovernmental agency forming part of the World Health Organisation of the United Nations....
(IARC) stated in 2005 that
COC increase the risk of cancers of the breast (among current and recent users), cervix and liver (among populations at low risk of hepatitis B virus infection). Research into the relationship between breast cancer
Breast cancer
Breast cancer is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas...
risk and hormonal contraception
Hormonal contraception
Hormonal contraception refers to birth control methods that act on the endocrine system. Almost all methods are composed of steroid hormones, although in India one selective estrogen receptor modulator is marketed as a contraceptive. The original hormonal method—the combined oral contraceptive...
is complex and seemingly contradictory.
The large 1996 collaborative reanalysis of individual data on over 150,000 women in 54 studies of breast cancer found that: "The results provide strong evidence for two main conclusions. First, while women are taking combined oral contraceptives and in the 10 years after stopping there is a small increase in the relative risk of having breast cancer diagnosed. Second, there is no significant excess risk of having breast cancer diagnosed 10 or more years after stopping use. The cancers diagnosed in women who had used combined oral contraceptives were less advanced clinically than those diagnosed in women who had never used these contraceptives."
This data has been interpreted to suggest that oral contraceptives have little or no biological effect on breast cancer development, but that women who seek gynecologic care to obtain contraceptives have more early breast cancers detected through screening. It has been estimated that, while taking the pill, there are approximately 0.5 excess cases of breast cancer per 10,000 women aged 16–19, and approximately 5 excess cases per 10,000 women aged 25–29.
Weight
The same 1992 French review article noted that in the subgroup of adolescents 15–19 years of age in the 1982 National Survey of Family Growth (NSFG)National Center for Health Statistics
National Center for Health Statistics is a division of the United States federal agency the Centers for Disease Control and Prevention . As such, NCHS is under the United States Department of Health and Human Services...
who had stopped taking the Pill, 20–25% reported they stopped taking the Pill because of either acne
Acne vulgaris
Acne vulgaris is a common human skin disease, characterized by areas of skin with seborrhea , comedones , papules , pustules , Nodules and possibly scarring...
or weight gain, and another 25% stopped because of fear of cancer. A 1986 Hungarian study comparing two high-dose estrogen (both 50 µg ethinyl estradiol) pills found that women using a lower-dose biphasic levonorgestrel formulation (50 µg levonorgestrel x 10 days + 125 µg levonorgestrel x 11 days) reported a significantly lower incidence of weight gain compared to women using a higher-dose monophasic levonorgestrel formulation (250 µg levonorgestrel x 21 days).
Many clinicians consider the public perception of weight gain on the Pill to be inaccurate and dangerous. The aforementioned 1992 French review article noted that one unpublished 1989 study by Professor Elizabeth Connell at Emory University
Emory University
Emory University is a private research university in metropolitan Atlanta, located in the Druid Hills section of unincorporated DeKalb County, Georgia, United States. The university was founded as Emory College in 1836 in Oxford, Georgia by a small group of Methodists and was named in honor of...
of 550 women found that 23% of the 6% of women who discontinued the Pill because of poor cycle control experienced subsequent unwanted pregnancies. A 2000 British review article concluded there is no evidence that modern low-dose pills cause weight gain, but that fear of weight gain contributed to poor compliance in taking the Pill and subsequent unintended pregnancy
Unintended pregnancy
Unintended pregnancies are those in which conception was not intended by the female sexual partner. Worldwide, 38% of pregnancies were unintended in 1999 . Unintended pregnancies are the primary cause of induced abortion, resulting in about 42 million induced abortions per year...
, especially among adolescents.
Sexuality
COCPs may increase natural vaginal lubricationVaginal lubrication
Vaginal lubrication is a lubricating fluid that is naturally produced in a woman's vagina. Vaginal lubrication or moistness is present at all times, but production increases significantly during a woman's sexual arousal in anticipation of sexual intercourse...
. Other women experience reductions in libido
Libido
Libido refers to a person's sex drive or desire for sexual activity. The desire for sex is an aspect of a person's sexuality, but varies enormously from one person to another, and it also varies depending on circumstances at a particular time. A person who has extremely frequent or a suddenly...
while on the pill, or decreased lubrication. Some researchers question a causal link between COCP use and decreased libido; a 2007 study of 1700 women found COCP users experienced no change in sexual satisfaction. A 2005 laboratory study of genital arousal tested fourteen women before and after they began taking COCPs. The study found that women experienced a significantly wider range of arousal responses after beginning pill use; decreases and increases in measures of arousal were equally common.
A 2006 study of 124 pre-menopausal women measured sex hormone binding globulin
Sex hormone binding globulin
Sex hormone-binding globulin or sex steroid-binding globulin is a glycoprotein that binds to sex hormones, to be specific, testosterone and estradiol...
(SHBG), including before and after discontinuation of the oral contraceptive Pill. Women continuing use of oral contraceptives had SHBG levels four times higher than those who never used it, and levels remained elevated even in the group that had discontinued its use. Theoretically, an increase in SHBG may be a physiologic response to increased hormone levels, but may decrease the free levels of other hormones, such as androgens, because of the unspecificity of its sex hormone binding.
Depression
Low levels of serotoninSerotonin
Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...
, a neurotransmitter in the brain, have been linked to depression
Clinical depression
Major depressive disorder is a mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem, and by loss of interest or pleasure in normally enjoyable activities...
. High levels of estrogen, as in first-generation COCPs, and progestin, as in some progestin-only contraceptives, have been shown to promote the lowering of brain serotonin levels by increasing the concentration of a brain enzyme that reduces serotonin. This observation, along with some small research studies have inspired speculation that the pill causes depression.
Progestin-only contraceptives are known to worsen the condition of women who are already depressed. However, current medical reference textbooks on contraception and major organizations such as the American ACOG, the WHO
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...
, and the United Kingdom's RCOG
Royal College of Obstetricians and Gynaecologists
The Royal College of Obstetricians and Gynaecologists is a professional association based in the UK. Its members, including people with and without medical degrees, work in the field of obstetrics and gynaecology, that is, pregnancy, childbirth, and female sexual and reproductive health...
agree that current evidence indicates low-dose combined oral contraceptives are unlikely to increase the risk of depression, and unlikely to worsen the condition in women that are currently depressed. Contraceptive Technology states that low-dose COCPs have not been implicated in disruptions of serotonin or tryptophan
Tryptophan
Tryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. It is encoded in the standard genetic code as the codon UGG...
. However, some studies provide evidence to contradict this last claim.
Hypertension
Bradykinin lowers blood pressure by causing blood vessel dilation. Certain enzymes are capable of breaking down bradykinin ( Angiotensin Converting Enzyme, Aminopeptidase P). Progesterone can increase the levels of Aminopeptidase P (AP-P), thereby increasing the breakdown of bradykinin, which increases the risk of developing hypertension.Other effects
Other side effects associated with low-dose COCPs are leukorrheaLeukorrhea
Leukorrhea or leucorrhoea is a medical term that denotes a thick, whitish or yellowish vaginal discharge.There are many causes of leukorrhea, the usual one being estrogen imbalance...
(increased vaginal secretions), reductions in menstrual flow
Menstruation
Menstruation is the shedding of the uterine lining . It occurs on a regular basis in sexually reproductive-age females of certain mammal species. This article focuses on human menstruation.-Overview:...
, mastalgia
Mastalgia
Mastodynia, mastalgia or mammalgia are names for a medical symptom that means breast pain .Pain can range from minor discomfort to severely incapacitating pain...
(breast tenderness), and decrease in acne
Acne
Acne is a general term used for acneiform eruptions. It is usually used as a synonym for acne vulgaris, but may also refer to:*Acne aestivalis*Acne conglobata*Acne cosmetica*Acne fulminans*Acne keloidalis nuchae*Acne mechanica...
. Side effects associated with older high-dose COCPs include nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
, vomiting
Vomiting
Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...
, increases in blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
, and melasma
Melasma
Melasma is a tan or dark skin discoloration. Although it can affect anyone, melasma is particularly common in women, especially pregnant women and those who are taking oral or patch contraceptives or hormone replacement therapy medications...
(facial skin discoloration); these effects are not strongly associated with low-dose formulations.
Excess estrogen, such as from birth control pills, appears to increase cholesterol levels in bile and decrease gallbladder movement, which can lead to gallstones.
Progestins found in certain formulations of oral contraceptive pills can limit the effectiveness of weight training
Weight training
Weight training is a common type of strength training for developing the strength and size of skeletal muscles. It uses the weight force of gravity to oppose the force generated by muscle through concentric or eccentric contraction...
to increase muscle mass. This effect is caused by the ability of some progestins to inhibit androgen receptor
Androgen receptor
The androgen receptor , also known as NR3C4 , is a type of nuclear receptor that is activated by binding of either of the androgenic hormones testosterone or dihydrotestosterone in the cytoplasm and then translocating into the nucleus...
s.
One study claims that the pill may affect what male body odors a woman prefers, which may in turn influence her selection of partner.
Contraindications
Combined oral contraceptives are generally accepted to be contraindicated in women with pre-existing cardiovascular diseaseCardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
, in women who have a familial tendency to form blood clots (such as familial factor V Leiden
Factor V Leiden
Factor V Leiden is the name given to a variant of human factor V that causes a hypercoagulability disorder. In this disorder the Leiden variant of factor V cannot be inactivated by activated protein C. Factor V Leiden is the most common hereditary hypercoagulability disorder amongst Eurasians...
), women with severe obesity
Obesity
Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...
and/or hypercholesterolemia
Hypercholesterolemia
Hypercholesterolemia is the presence of high levels of cholesterol in the blood. It is not a disease but a metabolic derangement that can be caused by many diseases, notably cardiovascular disease...
(high cholesterol level), and in smokers
Tobacco smoking
Tobacco smoking is the practice where tobacco is burned and the resulting smoke is inhaled. The practice may have begun as early as 5000–3000 BCE. Tobacco was introduced to Eurasia in the late 16th century where it followed common trade routes...
over age 40.
COC are also contraindicated for women with liver tumors, hepatic adenoma or severe cirrhosis of the liver, and for those with known or suspected breast cancer. (WHO category 4).
Health benefits
Overall, use of oral contraceptives appears to slightly reduce all-cause mortality, with a rate ratioRate ratio
A rate ratio in epidemiology is calculated to compare the rate of events occurring at any given point in time.Rate Ratio = Incidence Rate 1/Incidence Rate 2Where incidence rate is the occurrence of an event over person-time, for example person-years....
for overall mortality of 0.87 (confidence interval
Confidence interval
In statistics, a confidence interval is a particular kind of interval estimate of a population parameter and is used to indicate the reliability of an estimate. It is an observed interval , in principle different from sample to sample, that frequently includes the parameter of interest, if the...
: 0.79–0.96) when comparing ever-users of OCs with never-users.
The use of oral contraceptives (birth control pills) for five years or more decreases the risk of ovarian cancer in later life by 50%. Combined oral contraceptive use reduces the risk of ovarian cancer
Ovarian cancer
Ovarian cancer is a cancerous growth arising from the ovary. Symptoms are frequently very subtle early on and may include: bloating, pelvic pain, difficulty eating and frequent urination, and are easily confused with other illnesses....
by 40% and the risk of endometrial cancer
Endometrial cancer
Endometrial cancer refers to several types of malignancies that arise from the endometrium, or lining, of the uterus. Endometrial cancers are the most common gynecologic cancers in the United States, with over 35,000 women diagnosed each year. The incidence is on a slow rise secondary to the...
by 50% compared to never users. The risk reduction increases with duration of use, with an 80% reduction in risk for both ovarian and endometrial cancer with use for more than 10 years. The risk reduction for both ovarian and endometrial cancer persists for at least 20 years.
Taking oral contraceptives also reduces the risk of colorectal cancer, and improves conditions such as pelvic inflammatory disease, dysmenorrhea, premenstrual syndrome, and acne. Additionally, birth control pills reduce symptoms of polycystic ovary syndrome, and decrease the risk of anemia.
Use of combined oral contraceptives is associated with a reduced risk of endometriosis
Endometriosis
Endometriosis is a gynecological medical condition in which cells from the lining of the uterus appear and flourish outside the uterine cavity, most commonly on the ovaries. The uterine cavity is lined by endometrial cells, which are under the influence of female hormones...
, giving a relative risk of endometriosis of 0.63 during active use, yet with limited quality of evidence according to a systematic review
Systematic review
A systematic review is a literature review focused on a research question that tries to identify, appraise, select and synthesize all high quality research evidence relevant to that question. Systematic reviews of high-quality randomized controlled trials are crucial to evidence-based medicine...
.
Formulations
Oral contraceptives come in a variety of formulations. The main division is between combined oral contraceptive pills, containing both estrogenEstrogen
Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...
and progestin
Progestin
A progestin is a synthetic progestogen that has progestinic effects similar to progesterone. The two most common uses of progestins are for hormonal contraception , and to prevent endometrial hyperplasia from unopposed estrogen in hormone replacement therapy...
s and progestin only pills. Combined oral contraceptive pills also come in varying types, including varying doses of estrogen, and whether the dose of estrogen or progestin changes from 1 week to the next.
Non-contraceptive uses
The hormones in "the Pill" can also be used to treat other medical conditions, such as polycystic ovary syndromePolycystic ovary syndrome
Polycystic ovary syndrome is one of the most common female endocrine disorders. PCOS is a complex, heterogeneous disorder of uncertain aetiology, but there is strong evidence that it can to a large degree be classified as a genetic disease....
(PCOS), endometriosis
Endometriosis
Endometriosis is a gynecological medical condition in which cells from the lining of the uterus appear and flourish outside the uterine cavity, most commonly on the ovaries. The uterine cavity is lined by endometrial cells, which are under the influence of female hormones...
, adenomyosis
Adenomyosis
Adenomyosis is a medical condition characterized by the presence of ectopic glandular tissue found in muscle. The term adenomyosis is derived from the terms adeno- , myo- , and -osis...
, menstruation-related anemia and painful menstruation (dysmenorrhea
Dysmenorrhea
Dysmenorrhea is a gynecological medical condition of pain during menstruation that interferes with daily activities, as defined by ACOG and others. Still, dysmenorrhea is often defined simply as menstrual pain, or at least menstrual pain that is excessive...
). In addition, oral contraceptives are often prescribed as medication for mild or moderate acne. The pill can also induce menstruation on a regular schedule for women bothered by irregular menstrual cycles or disorders where there is dysfunctional uterine bleeding
Dysfunctional uterine bleeding
Dysfunctional Uterine Bleeding is abnormal genital tract bleeding based in the uterus and found in the absence of demonstrable structural or organic pathology.usually due to hormonal disturbances....
. In addition, the Pill provides some protection against breast growth that is not cancer, ectopic pregnancy, vaginal dryness and menopause-related painful intercourse.
Social and cultural impact
The Pill was approved by the FDA in the early 1960s; its use spread rapidly in the late part of that decade, generating an enormous social impact. TimeTime (magazine)
Time is an American news magazine. A European edition is published from London. Time Europe covers the Middle East, Africa and, since 2003, Latin America. An Asian edition is based in Hong Kong...
magazine placed the pill on its cover in April, 1967. In the first place, it was more effective than most previous reversible methods of birth control, giving women unprecedented control over their fertility. Its use was separate from intercourse, requiring no special preparations at the time of sexual activity that might interfere with spontaneity or sensation, and the choice to take the Pill was a private one. This combination of factors served to make the Pill immensely popular within a few years of its introduction.
Claudia Goldin, among others, argue that this new contraceptive technology was a key player in forming women's modern economic role, in that it prolonged the age at which women first married allowing them to invest in education and other forms of human capital as well as generally become more career-oriented. Soon after the birth control pill was legalized, there was a sharp increase in college attendance and graduation rates for women. From an economic point of view, the birth control pill reduced the cost of staying in school. The ability to control fertility without sacrificing sexual relationships allowed women to make long term educational and career plans.
Because the Pill was so effective, and soon so widespread, it also heightened the debate about the moral and health consequences of pre-marital sex and promiscuity. Never before had sexual activity been so divorced from reproduction. For a couple using the Pill, intercourse became purely an expression of love, or a means of physical pleasure, or both; but it was no longer a means of reproduction. While this was true of previous contraceptives, their relatively high failure rates and their less widespread use failed to emphasize this distinction as clearly as did the Pill. The spread of oral contraceptive use thus led many religious figures and institutions to debate the proper role of sexuality and its relationship to procreation. The Roman Catholic Church
Roman Catholic Church
The Catholic Church, also known as the Roman Catholic Church, is the world's largest Christian church, with over a billion members. Led by the Pope, it defines its mission as spreading the gospel of Jesus Christ, administering the sacraments and exercising charity...
in particular, after studying the phenomenon of oral contraceptives, re-emphasized the stated teaching on birth control in the 1968 papal encyclical Humanae Vitae
Humanae Vitae
Humanae Vitae is an encyclical written by Pope Paul VI and issued on 25 July 1968. Subtitled On the Regulation of Birth, it re-affirms the traditional teaching of the Catholic Church regarding married love, responsible parenthood, and the continuing proscription of most forms of birth...
. The encyclical reiterated the established Catholic teaching that artificial contraception distorts the nature and purpose of sex.
A backlash against oral contraceptives occurred in the early and mid-1970s, when reports and speculations appeared that linked the use of the Pill to breast cancer
Breast cancer
Breast cancer is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas...
. Until then, many women in the feminist movement had hailed the Pill as an "equalizer" that had given them the same sexual freedom as men had traditionally enjoyed. This new development, however, caused many of them to denounce oral contraceptives as a male invention designed to facilitate male sexual freedom with women at the cost of health risk to women.
The United States Senate
United States Senate
The United States Senate is the upper house of the bicameral legislature of the United States, and together with the United States House of Representatives comprises the United States Congress. The composition and powers of the Senate are established in Article One of the U.S. Constitution. Each...
began hearings on the Pill in 1970 and there were different viewpoints heard from medical professionals. Dr. Michael Newton, President of the College of Obstetricians and Gynecologists said:
"The evidence is not yet clear that these still do in fact cause cancer or related to it. The FDA Advisory Committee made comments about this, that if there wasn't enough evidence to indicate whether or not these pills were related to the development of cancer, and I think that's still thin; you have to be cautious about them, but I don't think there is clear evidence, either one way or the other, that they do or don't cause cancer."
Another physician, Dr. Roy Hertz of the Population Council
Population Council
The Population Council is an international, nonprofit, non-governmental organization. The Council conducts biomedical, social science, and public health research and helps build research capacities in developing countries. One-third of its research relates to HIV and AIDS; its other major program...
, said that anyone who takes this should know of "our knowledge and ignorance in these matters" and that all women should be made aware of this so she can decide to take the Pill or not.
The Secretary of Health, Education, and Welfare at the time, Robert Finch
Robert Finch
Robert Hutchison Finch was a Republican politician from La Canada Flintridge, California. Born in Tempe, Arizona, he was the son of Robert L. Finch, a member of the Arizona House of Representatives....
announced the federal government had accepted a compromise warning statement which would accompany all sales of birth control pills.
At the same time, society was beginning to take note of the impact of the Pill on traditional gender roles. Women now did not have to choose between a relationship and a career; singer Loretta Lynn
Loretta Lynn
Loretta Lynn is an American country music singer-songwriter, author and philanthropist. Born in Butcher Hollow, Kentucky to a coal miner father, Lynn married at 13 years old, was a mother soon after, and moved to Washington with her husband, Oliver Lynn. Their marriage was sometimes tumultuous; he...
commented on this in her 1974 album with a song entitled "The Pill
The Pill (song)
"The Pill" is a 1975 country music song recorded by Loretta Lynn. It is one of her best known songs as well as the most controversial record of her career...
", which told the story of a married woman's use of the drug to liberate herself from her traditional role as wife and mother.
It can be noted that the spread of the use of the contraceptive pill in the late 1960s lead to a rise in female employment. Women no longer had to choose between having a relationship and a career and could actively pursue both. This is evidenced by the fact that there was a dramatically large increase in female employment at the time the pill became available. States that allowed unmarried women to use the pill were also those that had higher rates of females in the workforce, especially in advanced professional careers.
Environmental impact
A woman using COCPs excretes from her urineUrine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
and feces
Feces
Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...
natural estrogen
Estrogen
Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...
s, estrone
Estrone
Estrone is an estrogenic hormone secreted by the ovary as well as adipose tissue.Estrone is one of several natural estrogens, which also include estriol and estradiol...
(E1) and estradiol
Estradiol
Estradiol is a sex hormone. Estradiol is abbreviated E2 as it has 2 hydroxyl groups in its molecular structure. Estrone has 1 and estriol has 3 . Estradiol is about 10 times as potent as estrone and about 80 times as potent as estriol in its estrogenic effect...
(E2), and synthetic estrogen ethinylestradiol
Ethinylestradiol
Ethynylestradiol , also ethynyl estradiol , is a derivative of estradiol. Ethynyl estradiol is an orally bio-active estrogen used in almost all modern formulations of combined oral contraceptive pills...
(EE2) into water treatment
Water treatment
Water treatment describes those processes used to make water more acceptable for a desired end-use. These can include use as drinking water, industrial processes, medical and many other uses. The goal of all water treatment process is to remove existing contaminants in the water, or reduce the...
plants.
These hormones can pass through water treatment
Water treatment
Water treatment describes those processes used to make water more acceptable for a desired end-use. These can include use as drinking water, industrial processes, medical and many other uses. The goal of all water treatment process is to remove existing contaminants in the water, or reduce the...
plants and into rivers. Other forms of contraception, such as the contraceptive patch
Contraceptive patch
A contraceptive patch is a transdermal patch applied to the skin that releases synthetic estrogen and progestin hormones to prevent pregnancy. They have been shown to be as effective as the combined oral contraceptive pill with perfect use, and the patch may be more effective in typical use.The...
, use the same synthetic estrogen (EE2) that is found in COCPs, and can add to the hormonal concentration in the water when flushed down the toilet. This excretion
Excretion
Excretion is the process by which waste products of metabolism and other non-useful materials are eliminated from an organism. This is primarily carried out by the lungs, kidneys and skin. This is in contrast with secretion, where the substance may have specific tasks after leaving the cell...
is shown to play a role in causing endocrine disruption, which affects the sexual development and the reproduction, in wild fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
populations in segments of streams contaminated by treated sewage effluents.
A study done in British rivers supported the hypothesis that the incidence and the severity of intersex wild fish populations were significantly correlated with the concentrations of the E1, E2, and EE2 in the rivers.
A review of activated sludge plant
Activated sludge
Activated sludge is a process for treating sewage and industrial wastewaters using air and a biological floc composed of bacteria and protozoans.-Purpose:...
performance found estrogen removal rates varied considerably but averaged 78% for estrone, 91% for estradiol, and 76% for ethinylestradiol (estriol
Estriol
Estriol is one of the three main estrogens produced by the human body.-Synthesis:Estriol is only produced in significant amounts during pregnancy as it is made by the placenta from 16-Hydroxydehydroepiandrosterone sulfate , an androgen steroid made in the fetal liver and adrenal glands.The human...
effluent concentrations are between those of estrone and estradiol, but estriol is a much less potent endocrine disruptor to fish).
Effluent concentrations of ethinylestradiol are lower than estradiol which are lower than estrone, but ethinylestradiol is more potent than estradiol which is more potent than estrone in the induction of intersex fish and synthesis of vitellogenin
Vitellogenin
Vitellogenin is a synonymous term for the gene and the expressed protein. The protein molecule is classified as a glycolipoprotein, having properties of a sugar, fat and protein...
in male fish.
External links
- The Birth Control Pill—‚CBC Digital Archives
- The Pill—PBS.org
- The Birth of the Pill—slide show by LifeLife (magazine)Life generally refers to three American magazines:*A humor and general interest magazine published from 1883 to 1936. Time founder Henry Luce bought the magazine in 1936 solely so that he could acquire the rights to its name....
magazine