Dayton Children’s Hospital

Amniotic Band Syndrome

What is amniotic band syndrome?

Amniotic band syndrome occurs when thin strands of tissue form inside the amniotic sac (the bag of fluid that surrounds your fetus) and tangle around the fetus like strings or rubber bands. These strands, called amniotic bands, make creases in the fetus’s tissue. This usually happens between 28 days after conception to week 18 of pregnancy. Sometimes the amniotic bands are very minor and superficial, but other times, they can constrict all the way to the bone. Untreated, the bands become tighter around the body part they are attached to, which is why amniotic band syndrome often leads to amputation, severe deformities, or in rare cases, death.

No one knows for certain exactly what causes amniotic band syndrome, but many physicians and researchers agree that it starts with the rupture of the amnion (a thin sac that forms around the fetus that protects it) early in pregnancy. Usually, this happens between 4 and 18 weeks of pregnancy. Bands of amnion then encircle parts of the fetus’s body. The rupture of the amnion appears to be random and is not related to anything the mother did or did not do during pregnancy. Further, it is unlikely to occur again in another pregnancy.

How is amniotic band syndrome diagnosed?

An ultrasound detects amniotic band syndrome. If your doctor suspects amniotic band syndrome, there will be another ultrasound to look for other abnormalities in the fetus. Doppler blood flow studies can be used to measure how severely the blood flow is restricted. After the testing your doctor will discuss with you the findings and the severity of the amniotic band syndrome.

How is amniotic band syndrome treated?

A fetus with amniotic band syndrome should pose no increased risk for the mother during pregnancy. However, there is an increased risk of fetal anomalies and premature labor and delivery.

Deformities caused by amniotic band syndrome are typically treated after the baby is born. Due to wide variations in how a baby can be affected, evaluation by several pediatric specialists may be necessary. A treatment plan will be developed based on your baby’s individual needs. If your baby requires surgery, he or she will most likely wait to have surgery until he or she is about 6 months to 1 year old. Some babies will need only one surgery while others need more. The goal of surgery is to improve the appearance and function of the affected body part.

However, if amniotic bands restrict blood flow, fetal surgery may be recommended. This surgery cuts the amniotic bands that could cause amputation or constrict the umbilical cord. This type of surgery is performed through a small camera inserted into the uterus. Your doctor may use a laser to cut the bands and free the baby from them. This freedom gives the baby a better chance to grow in a more normal way.

What can I expect after surgery?

After surgery, your baby will be cared for by our multidisciplinary team of pediatric specialists. A treatment plan will be developed based on your baby’s individual needs.