In the developing 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...

, the ductus arteriosus (DA), also called the ductus Botalli, is a shunt

Shunt (medical)

In medicine, a shunt is a hole or a small passage which moves, or allows movement of fluid from one part of the body to another. The term may describe either congenital or acquired shunts; and acquired shunts may be either biological or mechanical.* Cardiac shunts may be described as...

 connecting the pulmonary artery

Pulmonary artery

The pulmonary arteries carry deoxygenated blood from the heart to the lungs. They are the only arteries that carry deoxygenated blood....

 to the aortic arch

Aorta

The aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...

. It allows most of the blood

Blood

Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

 from the right ventricle

Right ventricle

The right ventricle is one of four chambers in the human heart. It receives deoxygenated blood from the right atrium via the tricuspid valve, and pumps it into the pulmonary artery via the pulmonary valve and pulmonary trunk....

 to bypass the fetus's fluid-filled lung

Lung

The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...

s. Upon closure at birth, it becomes the ligamentum arteriosum

Ligamentum arteriosum

The ligamentum arteriosum is a small ligament attached to the superior surface of the pulmonary trunk and the inferior surface of the aortic arch...

. There are two other fetal shunts, the ductus venosus

Ductus venosus

In the fetus, the ductus venosus shunts approximately half of the blood flow of the umbilical vein directly to the inferior vena cava. Thus, it allows oxygenated blood from the placenta to bypass the liver. In conjunction with the other fetal shunts, the foramen ovale and ductus arteriosus, it...

 and the foramen ovale

Foramen ovale (heart)

In the fetal heart, the foramen ovale , also ostium secundum of Born or falx septi, allows blood to enter the left atrium from the right atrium. It is one of two fetal cardiac shunts, the other being the ductus arteriosus...

.

Patent ductus arteriosus

Failure of a child's DA to close after birth results in a condition called patent ductus arteriosus

Patent ductus arteriosus

Patent ductus arteriosus is a congenital disorder in the heart wherein a neonate's ductus arteriosus fails to close after birth. Early symptoms are uncommon, but in the first year of life include increased work of breathing and poor weight gain...

 and the generation of a left-to-right shunt

Cardiac shunt

Cardiac shunts is when the blood flow follows a pattern in the heart that deviates from the normal circuit of the circulatory system. It may be described as right-left, left-to-right or bidirectional, or as systemic-to-pulmonary or pulmonary-to-systemic. The direction may be controlled by left...

. If left uncorrected, patency leads to pulmonary hypertension

Pulmonary hypertension

In medicine, pulmonary hypertension is an increase in blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, and other symptoms, all of which are exacerbated by exertion...

 and possibly congestive heart failure

Congestive heart failure

Heart failure often called congestive heart failure is generally defined as the inability of the heart to supply sufficient blood flow to meet the needs of the body. Heart failure can cause a number of symptoms including shortness of breath, leg swelling, and exercise intolerance. The condition...

 and cardiac arrhythmias. Prostaglandins are responsible for maintaining the ductus arteriosus.
Closure may be induced with NSAIDs because these drugs inhibit prostaglandin synthesis.

A patent ductus arteriosus affects around 40% of infants with Down syndrome

Down syndrome

Down syndrome, or Down's syndrome, trisomy 21, is a chromosomal condition caused by the presence of all or part of an extra 21st chromosome. It is named after John Langdon Down, the British physician who described the syndrome in 1866. The condition was clinically described earlier in the 19th...

 (DS). A failure to thrive

Failure to thrive

Failure to thrive is a medical term which is used in both pediatric and adult human medicine, as well as veterinary medicine ....

is a very common sign of this condition.

External links

• Circulatory changes at birth at berkeley.edu
• http://docs.google.com/gview?a=v&pid=gmail&attid=0.2&thid=12229efed1dc838e&mt=application%2Fpdf Ambient Air Pollution and Cardiovascular Malformations in Atlanta Georgia. This is a study showing a correlation between air pollution, particulate matter greater than 10 micrometers, that has statistical significance in increasing the risk of patent ductus arteriosus when inhaled by pregnant women at 3-7 weeks of pregnancy.