fetal circulation

The circulation that serves the fetus in utero with the placenta functioning to supply oxygen & deliver nutrition & to eliminate CO₂ & nitrogenous waste. Oxygenated blood from the placenta is delivered to the fetus by the umbilical vein. Oxygenated blood from the venous system enters the right atrium & right ventricle, bypasses the lungs via the ductus arteriosus connecting the pulmonary artery with the aortic arch. Closure of the ductus arteriosis & birth & obliteration of the umbilical vein initiates circulation through the lungs & the normal postnatal circulatory system.

References

Stedman's Medical Dictionary 27th ed, Williams & Wilkins, Baltimore, 1999