While a baby grows in the womb, there is a normal opening between the left and right atria (upper chambers) of the heart. If this opening fails to close naturally soon after the baby is born, the hole is called patent foramen ovale (PFO).

A patent foramen ovale (PFO) allows blood to bypass the lungs. A baby's lungs are not used when it grows in the womb, so the hole does not cause problems in an unborn infant. The opening is supposed to close soon after birth, but sometimes it does not. In about 1 out of 3 or 4 people, the opening never closes.

The cause of a PFO is unknown. There are no known risk factors.

Infants with a patent foramen ovale and no other heart defects do not have symptoms.

An echocardiogram can be done to diagnose a PFO. If the PFO is not easily seen, a cardiologist can perform a "bubble test." Saline solution (salt water) is injected into the body. If a PFO exists, air bubbles will occur from the right to left side of the heart.

This condition is not treated unless other heart abnormalities exist or if you had a stroke caused by a blood clot to the brain.

Closure of the PFO usually requires invasive surgery by a specifically trained cardiologist, who uses a special tool to permanently seal the PFO shut.

The infant will have normal health in the absence of other heart defects.

Unless there are other associated defects, there are usually no complications associated with PFO. There have been some studies suggesting that older patients with PFOs have a higher rate of a certain type of stroke (thromboembolic). The reason for this is that older people frequently develop blood clots in the veins in their legs. These clots can sometimes travel from their original site to the right side of their heart.

If PFO is present, the clot can then pass from the right side to the left side from whence it can travel to the brain and become lodged there, preventing blood flow to that part of the brain (stroke).

Call your health care provider if your baby turns blue when crying or defecating. Usually, however, this disorder is only discovered incidentally when a cardiologist performs an echocardiogram (ultrasound of the heart) to evaluate an unrelated heart murmur.