For Patients/Families

Persistent fetal circulation
An obstetrician who has subspecialized in the care of pregnant women and unborn babies. If you have a complicated pregnancy or one at high risk of having complications, you may be referred to one of these physicians. They are often the specialists who perform the level 2 or detailed ultrasound examination.

Persistent fetal circulationThe circulation of blood in the fetus is somewhat different from that of the baby after birth. This transition from fetal to neonatal circulation is one of the major physiologic changes after delivery. Before birth, the lungs are collapsed and the blood pressure in the lungs is quite high. This results in a very low blood flow through the lungs. After delivery, the lungs expand the and the blood pressure in the lungs decreases.

In some babies, although the lungs expand the blood vessels in the lungs remain constricted resulting in persistently high blood pressure in the lungs. This reduces the amount of blood that the infant can pump through the lungs. This decreased blood flow through the lungs after birth is called persistent fetal circulation because it is a persistence of the pattern of blood flow normally seen prior to birth during the fetal period.

Infections, malformations of the lung or diaphragm, and lung immaturity can all cause persistent fetal circulation. This is a very serious, although infrequent, newborn problem. Several new treatments for persistent fetal circulation have been developed in the past few years and have increased survival of infants with this problem.