Amniotic Band Syndrome

Amniotic band syndrome, or ABS, is a rare condition that affects the fetus during pregnancy. About 1 in 1,200 babies are impacted by amniotic band syndrome. With ABS, thin, fibrous strands of tissue develop inside the amniotic sac and then entrap the fetus’s limbs, digits, or other fetal body parts.

The fibrous bands can limit tissue growth or cause necrosis, resulting in limb and appendage disfigurement or even amputation inside the womb if they are wound tightly enough to constrict blood flow. ABS can affect the unborn baby’s legs, feet, and toes. For example, if a band wraps around the peroneal nerve in the leg, it can result in clubfoot.

Amniotic band syndrome is also known as Streeter bands, congenital ring constriction, and constriction band syndrome. It is generally considered a random occurrence without genetic influence; however, there is some research indicating that early rupture of the inner membrane of the amniotic sac can cause ABS.