Fetal circulation

Fetal circulation refers to the circulatory system of a human fetus, often considered to be the most important part of fetal development. This system is unique in that it includes three shunts, which are blood vessels that direct blood flow away from the lungs and liver, as these organs are not yet functional in the fetus.

Fetal Circulatory System

Overview

The fetal circulatory system is different from adult circulation. It includes three shunts to reroute blood from the lungs and liver, which are not yet functional in the fetus. These shunts are the ductus venosus, the foramen ovale, and the ductus arteriosus.

Shunts

Ductus Venosus

The Ductus Venosus is a small vein that carries oxygenated blood from the umbilical vein to the inferior vena cava, bypassing the liver.

Foramen Ovale

The Foramen Ovale is a hole in the heart that allows blood to flow directly from the right atrium to the left atrium, bypassing the lungs.

Ductus Arteriosus

The Ductus Arteriosus is a small artery connecting the pulmonary artery to the aorta, allowing blood to bypass the lungs.

Changes at Birth

At birth, the umbilical cord is clamped, and the baby begins to breathe air. This causes the three shunts to close, and the baby's circulatory system begins to function like an adult's.

See Also

• Cardiovascular System
• Fetal Development
• Pregnancy