The foramen ovale has an important role in the health of the fetal circulatory system. During fetal development, this hole in the wall between the heart’s upper chambers allows blood to bypass the lungs, which aren’t yet needed. After birth, however, the foramen ovale should naturally close as blood is routed to the working lungs.
If the foramen ovale doesn’t close, however, it’s known as the congenital heart defect patent foramen ovale, or PFO. This condition is relatively common, occurring in about one in four people.
Much is unknown about the condition. This congenital heart deformity’s cause is unknown, there are no known risk factors, and infants who have patent foramen ovale and no other heart defects often don’t have symptoms. Most people never know they have the defect.
Doctors might suspect the condition if they hear a heart murmur during a routine physical exam or while testing newborns for other reasons. Pediatricians or pediatric cardiologists traditionally base the diagnosis on results from an echocardiogram. If needed, they might also perform a “bubble test,” where they inject saline and use ultrasound to watch for tiny air bubbles moving from the right to left sides of the heart to confirm the diagnosis.
Parents will be happy to know this condition is generally not treated, unless the patent foramen ovale is accompanied by other heart problems or if the person has had a stroke.
Physicians might recommend a procedure to close the patent foramen ovale when children are having surgery to correct other congenital heart defects or if a child has low blood oxygen levels due to the unclosed hole.
If treatment is needed, physicians generally turn to cardiac catheterization or surgical repair, during which they permanently seal the opening.
Newborns who have no other heart defects can look forward to a normally healthy life, with no restrictions. Some studies have suggested unexplained stroke and migraine with aura are more common in people with patent foramen ovale. But these associations remain controversial and research is ongoing.
Reviewed by Dr. Sara Connolly, August 2019
- The foramen ovale, a hole created to bypass blood flow to the lungs in the fetal heart, naturally closes after birth.
- Patent foramen ovale is a congenital heart defect in which this hole fails to close properly.
- Most children with the condition never know they have it, and it is usually not treated unless a child has other congenital heart defects.