Persistent Pulmonary Hypertension of the Newborn

Persistent pulmonary hypertension of the newborn (PPHN) occurs when a newborn's circulation system does not adapt to breathing outside the womb. While a fetus is in the womb, it gets its oxygen from its mother's placenta through the umbilical cords, so the lungs need little blood supply. There is high blood pressure in the lungs, so blood in the pulmonary artery is sent away from the lungs to the other organs through a fetal blood vessel, called the ductus arteriosus.

When a baby is born and takes its first breaths, the blood pressure in their lungs falls and there is an increased blood flow to the lungs, where oxygen and carbon dioxide are exchanged. The blood is then returned to the heart and pumped back out to the body. The ductus arteriosus constricts and permanently closes in the first day of life. However, in babies with PPHN, the pressure in the lungs remains high and the ductus arterious remains open, allowing blood to be directed away from the lungs.

PPHN is a rare, but life-threatening condition. It occurs most often in full-term or post-term babies who have had a difficult birth, or conditions such as infection or birth asphyxia, in which a baby receives an inadequate amount of oxygen during delivery.

Experts at UCSF Children's Hospital care for infants with PPHN in the William H. Tooley Intensive Care Nursery.

Reviewed by health care specialists at UCSF Children's Hospital.
Last updated May 8, 2007