During pregnancy, the fetal circulatory system works differently than after birth:

  • The fetus is connected by the umbilical cord to the placenta, the organ that develops and implants in the mother's uterus during pregnancy.
  • Through the blood vessels in the umbilical cord, the fetus receives all the necessary nutrition, oxygen and life support from the mother through the placenta.
  • Waste products and carbon dioxide from the fetus are sent back through the umbilical cord and placenta to the mother's circulation to be eliminated.