While a fetus grows in the uterus, its lungs are not functional. The foramen ovale allows blood to bypass the lungs so it does not cause issues in the fetus. The opening is supposed to close soon after birth, but sometimes it does not. In about 1 out of 4 people, the opening never closes. If it does not, it is called a patent foramen ovale (PFO). The cause of a patent foramen ovale is unknown.
What causes Patent foramen ovale?
While a fetus grows in the uterus, its lungs are not functional. The foramen ovale allows blood to bypass the lungs so it does not cause issues in the fetus. The opening is supposed to close soon after birth, but sometimes it does not. In about 1 out of 4 people, the opening never closes. If it does not, it is called a patent foramen ovale ({{ORGANIZATION}}). The cause of a patent foramen ovale is unknown.