Gestational hypertension or pregnancy-induced hypertension (PIH) is defined as the development of new arterial hypertension in a pregnant

Pregnancy

Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...

 woman after 20 weeks gestation without the presence of protein in the urine.

Conditions

There exist several hypertensive states of pregnancy:

Gestational hypertension

Gestational hypertension is usually defined as having a 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...

 higher than 140/90 without the presence of protein in the urine.

Preeclampsia

Pre-eclampsia is gestational hypertension (blood pressure greater than 140/90) plus proteinuria

Proteinuria

Proteinuria means the presence of anexcess of serum proteins in the urine. The protein in the urine often causes the urine to become foamy, although foamy urine may also be caused by bilirubin in the urine , retrograde ejaculation, pneumaturia due to a fistula, or drugs such as pyridium.- Causes...

 (>300 mg of protein in a 24-hour urine sample). Severe preeclampsia involves a blood pressure greater than 160/110, with additional medical sign

Medical sign

A medical sign is an objective indication of some medical fact or characteristic that may be detected by a physician during a physical examination of a patient....

s and symptom

Symptom

A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...

s.

Eclampsia

Eclampsia

Eclampsia , an acute and life-threatening complication of pregnancy, is characterized by the appearance of tonic-clonic seizures, usually in a patient who had developed pre-eclampsia...

This is when tonic-clonic seizure

Tonic-clonic seizure

Tonic–clonic seizures are a type of generalized seizure that affects the entire brain...

s appear in a pregnant woman with high blood pressure and proteinuria.

HELLP syndrome

HELLP syndrome

HELLP syndrome is a life-threatening obstetric complication usually considered to be a variant of pre-eclampsia. Both conditions usually occur during the later stages of pregnancy, or sometimes after childbirth.HELLP is an abbreviation of the main findings:...

This is a dangerous combination of three medical conditions: hemolytic anemia

Hemolytic anemia

Hemolytic anemia is a form of anemia due to hemolysis, the abnormal breakdown of red blood cells , either in the blood vessels or elsewhere in the human body . It has numerous possible causes, ranging from relatively harmless to life-threatening...

, elevated liver enzymes and low platelet count

Thrombocytopenia

Thrombocytopenia is a relative decrease of platelets in blood.A normal human platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. These limits are determined by the 2.5th lower and upper percentile, so values outside this range do not necessarily indicate disease...

.

Acute fatty liver of pregnancy

Acute fatty liver of pregnancy

Acute fatty liver of pregnancy is a rare life-threatening complication of pregnancy that occurs in the third trimester or the immediate period after delivery. It is thought to be caused by a disordered metabolism of fatty acids by mitochondria in the mother, caused by deficiency in the LCHAD enzyme...

This is sometimes included in the preeclamptic spectrum.

Pre-eclampsia and eclampsia are sometimes treated as components of a common syndrome.

Risk factors

• Family history of pre-eclampsia
• Pre-existing hypertension
  Hypertension
  Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
  
  
• Renal disease
• Diabetes mellitus
  Diabetes mellitus
  Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
  
  
• 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...
  
  
• Placental Abnormalities:

1. Hyperplacentosis:Excessive exposure to chronic villi.

2. Placental Ischemia.

• Multiple gestation (twins or triplets, etc.)
• Age 35 or greater
• Adolescent pregnancy
• New paternity
• African-American race
• ThrombophiliasThrombophilias(Anti phospholoipid syndrome,Protein C,S deficiency,Factor V Leiden)

Etiopathological Factors for Pre-eclampsia

• Failure to trophoblast invasion(abnormal Placentation)
• Vascular Endothelial Damage
• InflamatoryMediator(cytokines)
• Immunological intolerence between Maternal and Fetal tissues
• Coagulation Abnormalities
• Increased Oxygen free radicals
• Genetic Predisposition(Polygenic Disorders)
• Dietary Deficiency or excess.

Treatment

There is no specific treatment, but is monitored closely to rapidly identify pre-eclampsia and its life-threatening complications (HELLP syndrome and eclampsia).

Drug treatment options are limited, as many antihypertensive

Antihypertensive

The antihypertensives are a class of drugs that are used to treat hypertension . Evidence suggests that reduction of the blood pressure by 5 mmHg can decrease the risk of stroke by 34%, of ischaemic heart disease by 21%, and reduce the likelihood of dementia, heart failure, and mortality from...

s may negatively affect the fetus

Fetus

A fetus is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth.In humans, the fetal stage of prenatal development starts at the beginning of the 11th week in gestational age, which is the 9th week after fertilization.-Etymology and spelling variations:The...

; methyldopa

Methyldopa

Methyldopa is an alpha-adrenergic agonist psychoactive drug used as a sympatholytic or antihypertensive. Its use is now mostly deprecated following the introduction of alternative safer classes of agents...

, hydralazine

Hydralazine

Hydralazine is a direct-acting smooth muscle relaxant used to treat hypertension by acting as a vasodilator primarily in arteries and arterioles...

 and labetalol

Labetalol

Labetalol is a mixed alpha/beta adrenergic antagonist, which is used to treat high blood pressure.-Indications:...

 are most commonly used for severe pregnancy hypertension.

The fetus is at increased risk for a variety of life-threatening conditions, including pulmonary hypoplasia

Pulmonary hypoplasia

Pulmonary hypoplasia is incomplete development of the lungs, resulting in an abnormally low number or size of bronchopulmonary segments or alveoli. A congenital malformation, it most often occurs secondary to other fetal abnormalities that interfere with normal development of the lungs...

(immature lungs). If the dangerous complications appear after the fetus has reached a point of viability, even though still immature, then an early delivery may be warranted to save the lives of both mother and baby. An appropriate plan for labor and delivery includes selection of a hospital with provisions for advanced life support of newborn babies.