Amniotic Band Syndrome | Fetal Care and Treatment Center | UC Davis Children's Hospital

What is amniotic band syndrome?

Amnion is a thin, protective membrane that surrounds the baby in the uterus. If it ruptures, typically early in pregnancy, fibrous strands of amnion can end up floating in the amniotic sac. These string-like bands can attach to the baby’s developing body parts and cause injury. Untreated, the bands become tighter around the body part to which they are attached, which is why amniotic band syndrome often leads to amputation, limb deformity, webbed toes or fingers or defects of the head, face or spine.

Diagnosis

Amniotic band syndrome is typically diagnosed at or soon after birth, based on characteristic physical findings, including ring-like constrictions or amputation defects of the arms, legs, fingers or toes.

In some cases, the condition may be suspected before birth, based on results of specialized screenings such as fetal ultrasonography and amniocentesis. During an ultrasound examination, images can reveal signs of amniotic band syndrome. With amniocentesis, a needle is introduced into the amniotic sac and a sample of fluid is removed to check for alpha fetoprotein, a protein that the fetus produces. Raised levels of the protein may be associated with a number of abnormalities in a developing fetus, including amniotic band syndrome.

Treatment

If the amniotic band is touching an area of the fetus but not causing injury or cutting off blood flow, no surgery is necessary.

Minimally invasive fetal surgery can be an option if the amniotic band is threatening the baby’s life by impeding blood flow to a limb, entangling the umbilical cord, or threatening to cause a severe deforming or facial problem.

In fetoscopic or fetal image-guided surgery, only a small incision is needed to manipulate surgical instruments. The surgeon inserts a tiny scope in the mother’s uterus and uses instruments or laser energy to cut the amniotic band, using a combination of endoscopy and ultrasound to view the fetus. This procedure can immediately reduce the pressure on the affected extremity and allows it to develop normally, without any further damage. In severe cases, fetal surgery may be the best option.

Outcome

Every case of amniotic band syndrome is unique. Babies can typically be treated after birth by a reconstructive surgeon to repair any remaining physical abnormalities. In some cases, surgery prior to birth is possible.

Babies with amniotic band syndrome tend to do well, although limb function may be affected depending on the severity of the defect. Children are monitored throughout development for any problems associated with the disorder.