In fetal circulation, which statement is true?

• A. The umbilical vein carries blood to the fetus.
• B. The umbilical arteries carry blood to the fetus.
• C. Blood in the fetal circulation passes through the lungs first.
• D. The placenta receives deoxygenated blood from the fetus.

Answer: (A)

In fetal circulation, the main point is that oxygenated blood travels from the placenta to the fetus through the umbilical vein. This vessel brings the newborn the oxygen and nutrients exchanged across the placental barrier, supporting the developing tissues before birth. The umbilical arteries carry blood away from the fetus to the placenta (deoxygenated), not toward the fetus. The lungs aren’t used for oxygen exchange in the fetus—the blood bypasses them via fetal shunts like the foramen ovale and ductus arteriosus. The placenta does receive blood from the fetus via the umbilical arteries, where it unloads carbon dioxide and waste, and then returns oxygenated blood to the fetus via the umbilical vein. So the true statement that best captures the fetal blood flow is that the umbilical vein carries blood to the fetus.