Fetal Circulation: Key Concepts for Antepartum Education ...

The nurse is preparing a class for antepartum clients on fetal development. Which of the following statements is true regarding fetal circulation?

Select all that apply.

• A. There are high pressures in the fetal lungs causing decreased pulmonary circulation.

• B. Blood shunts from left to right in the fetal circulation.

• C. The ductus venosus allows freshly oxygenated blood to go to the fetal brain first.

• D. There are higher pressures in the right atrium in the fetal circulation.

• E. After birth, the fetal circulation system undergoes significant changes as the baby begins to breathe.

CORRECT ANSWER 

A, C, D, and E

EXPLANATION. 

• A. There are high pressures in the fetal lungs causing decreased pulmonary circulation.
   True — Because the fetal lungs are fluid-filled and not used for gas exchange, pulmonary vascular resistance is high, which limits blood flow through the lungs.

• B. Blood shunts from left to right in the fetal circulation.
   False — In fetal circulation, shunting goes right to left through the foramen ovale and ductus arteriosus to bypass the lungs.

• C. The ductus venosus allows freshly oxygenated blood to go to the fetal brain first.
   True — Oxygen-rich blood from the placenta passes through the ductus venosus into the inferior vena cava, then preferentially flows toward the brain and heart.

• D. There are higher pressures in the right atrium in the fetal circulation.
   True — Because the pulmonary circulation is constricted, blood returning from the body and placenta causes higher right atrial pressure compared to the left.

• E. After birth, the fetal circulation system undergoes significant changes as the baby begins to breathe.
   True — With the first breaths, pulmonary vascular resistance decreases, blood flows into the lungs, and shunts (foramen ovale, ductus arteriosus, ductus venosus) close.