Fetal and Newborn Circulation

• Fetal circulation involves unique adaptations that allow the fetus to bypass the lungs, as the placenta performs gas exchange.
• After birth, significant changes occur in the circulatory system, including the closure of the foramen ovale and the ductus arteriosus.

Placental Role

• In fetal circulation, the placenta is responsible for gas exchange, providing oxygen and nutrients to the fetus while removing waste products.
• This function bypasses the need for the fetal lungs to perform respiratory gas exchange.

Lung Bypass

• Fetal circulation is characterized by blood bypassing the lungs.

Foramen Ovale Closure

• At birth, the foramen ovale, which is an opening between the right and left atria in the fetal heart, closes.
• This closure separates the pulmonary and systemic circulations, establishing normal blood flow through the lungs.

Ductus Arteriosus Closure

• The ductus arteriosus, a blood vessel connecting the pulmonary artery to the aorta in fetal circulation, closes at birth.
• Closure of the ductus arteriosus prevents blood from bypassing the lungs and ensures that all blood passes through the pulmonary circulation for oxygenation.