- Fetal circulation: prenatal blood-flow pattern in which the placenta, not the lungs, oxygenates blood.
- Uses shunts (ductus venosus, foramen ovale, ductus arteriosus) to bypass the liver and lungs
Differences from Adult Circulation
Differences between fetal and adult circulation
Point
Oxygenation
- Fetal circulation
- By the placenta
- Adult circulation
- By the lungs
Pulmonary blood flow
- Fetal circulation
- Minimal; lungs collapsed, high resistance
- Adult circulation
- Full flow through expanded, low-resistance lungs
Portal circulation
- Fetal circulation
- Of little significance
- Adult circulation
- Significant