Obstetrics & Gynecology>>>>>Maternal-Fetal Physiology and Placentation
Question 2#

After delivery of a term newborn with Apgar scores of 2 at 1 minute and 7 at 5 minutes, you ask that blood from the umbilical arteries be collected for pH.

The umbilical arteries carry which of the following?

a. Oxygenated blood to the placenta
b. Oxygenated blood from the placenta
c. Deoxygenated blood to the placenta
d. Deoxygenated blood from the placenta
e. Mixed oxygenated blood from the placenta

Correct Answer is C


Deoxygenated fetal blood is returned directly to the placenta through the umbilical branches of the two hypogastric arteries. The umbilical arteries exit through the abdominal wall at the umbilicus and continue by way of the umbilical cord to the placenta. Deoxygenated blood circulates through the placenta then returns, oxygenated, to the fetus via the umbilical vein. The umbilical arteries atrophy and obliterate within 3 to 4 days after birth; remnants are called umbilical ligaments.