Which blood vessel carries oxygen from the placenta to the fetus?

The umbilical vein is responsible for carrying oxygen-rich blood from the placenta to the fetus. During pregnancy, the placenta serves as an organ that facilitates the exchange of oxygen, nutrients, and waste between the mother and the developing fetus. The umbilical vein specifically transports this oxygenated blood, which is crucial for fetal growth and development.

Once the oxygenated blood enters the fetus through the umbilical vein, it is delivered to the liver via the ductus venosus and then circulated through the body. This transport process is essential because the fetus relies entirely on the mother’s circulation for its oxygen supply until birth.

In contrast, the umbilical arteries carry deoxygenated blood from the fetus back to the placenta. The ductus venosus is involved in bypassing the liver, allowing some of the blood from the umbilical vein to flow directly into the inferior vena cava. The aorta then carries oxygenated blood to the fetus's systemic circulation but does not directly transport it from the placenta. Understanding this system is critical in obstetrics and midwifery, as it underscores the reliance of the fetus on maternal blood supply for oxygenation.