The fetal circulation allows the fetus to receive oxygen and nutrients from the placenta while bypassing the non-functional lungs. Oxygenated blood travels from the placenta through the umbilical vein to the inferior vena cava and then through the foramen ovale into the left atrium of the heart. It is then pumped through the aorta to deliver oxygen to tissues before returning to the right atrium. A small amount of blood passes through the ductus arteriosus and pulmonary arteries to the developing lungs, while most blood is shunted away from the lungs and back to the aorta. At birth, the foramen ovale and ductus arteriosus normally close as the lungs begin functioning

1. FETAL HEART CIRCULATION
VD. MANOJ JAGTAP
LECTURER, SHARIR RACHANA VIBHAG

2. Objectives
• Discuss anatomy and physiology of
fetal circulation
• Define specialized structures of fetal
circulation

3. Anatomy and Physiology
Fetal Circulation
 Umbilical cord
 2 umbilical arteries: return non-
oxygenated blood, fecal waste, CO2 to
placenta
 1umbilical vein: brings oxygenated blood
and nutrients to the fetus
• Fetus depends on placenta to meet O2
needs while organs continue formation
• Oxygenated blood flows from the placenta

6. • To the fetus via the umbilical vein
• After reaching fetus the blood flows through
the inferior vena cava
• Blood continues to travel from the inferior
vena cava to the ductus venosis
• Ductus Venosis
– Small amount of blood routed to growing liver
– Increased blood flow leads to large liver in
newborns

7. • Blood continues to travel up the inferior vena cava
• Empties into the right atrium of the heart
• The blood then passes to the left atrium through the
foramen ovale
• Foramen ovale
– Small opening in the septum of the heart
– Completely bypasses the non-functioning lungs

8. Foramen ovaleForamen ovale

9.  Blood continues journey to the left ventricle blood
is then pumped into the aorta
 Blood is circulated to the upper extremities
 Blood then returns to the right atrium
• From the right atrium, the blood goes to the right
ventricle then to the pulmonary arteries
• Pulmonary arteries
– Small amount goes to the maturing lungs
• Rest of blood is shunted away from lungs by Ductus
ateriosus back to aorta

11. • Blood travels back from aorta to the two
umbilical arteries to the placenta
• The placenta will re-supply the blood with
oxygen

12. What happens at birth?
Foramen ovale Closes shortly after birth,
fuses completely in first
year.
Ductus arteriousus Closes soon after birth,
becomes ligamentum
arteriousum in about 3
months.
Ductus venosus Ligamentum venosum
Umbilical arteries Medial umbilical ligaments
Umbilical vein Ligamentum teres

13. Problem with persistence
of fetal circulation
 Patent (open) Ductus arteriousus and patent
foramen ovale each characterize about 8% of
congenital heart defects.
 Both cause a mixing of oxygen-rich and oxygen-
poor blood; blood reaching tissues not fully
oxygenated. Can cause cyanosis.
 Surgical correction now available, ideally
completed around age two.
 Many of these defects go undetected until child
is at least school age.