Fetal circulation is the movement of blood within a developing fetus in the womb. the fetal circulation process is very interesting because it allows the fetus to get oxygen without breathing. Though the systems are entirely separate, the fetus gets processed oxygen from the mother’s own blood supply.
The fetus receives its supply of nutrients and oxygen from the placenta through the umbilical cord. Oxygenated blood pumps through the fetus’ liver and heart using the fetal circulatory system. It comes out again through the umbilical cord as deoxygenated blood and waste products which are collected by the placenta as it gives more oxygenated blood. The fetal circulatory system utilizes shunts called the ductus venosus, the ductus arteriosus and the foramen ovale to move the blood in the fetus. These shunts help bypass certain body parts which are not yet fully developed. The lungs are particularly protected at this stage.
At birth, the fetal circulatory system has to work to adapt quickly to the new environment. When the child take the first breath, the shunts are closed off as they sense the change in pressure in the circulatory system and allow the use of the lungs without rerouting the blood supply. Gradually, the fetal circulation system closes down.
Prolonged labor and congenital abnormalities complicate the fetal circulatory system. In some babies, the shunts do not close in time and continue to operate diverting blood away from the lungs. This causes pulmonary hypertension as blood is kept out of the lungs. With the aide of supplementary oxygen, the baby usually adjusts.