Fetal and Postnatal Circulation Notes

Umbilical Vein

• Carries oxygenated blood to the fetus.

Fetal Circulation

• In the fetal stage, the goal is for blood to return to the placenta because the placenta is a low-pressure system.
• The fetal heart directs blood away from high pressure areas.

Postnatal Circulation

• After birth, the role shifts to the lungs for oxygenation, requiring blood flow to the lungs.
• The placenta is no longer needed and becomes a high-pressure system.

Foramen Ovale

• A shortcut for fetal blood flow that should close within minutes after birth.
• After closure, the foramen ovale becomes the fossa ovale.

Fossa Ovale

• The closed form of the foramen ovale.
• Potential issues with the fossa ovale can cause strokes. This is a test question.