Amniotic Band Syndrome Pregnancy Complication

Amniotic band syndrome is a condition in which fibrous bands of tissue from a pregnant person's uterus wrap around a growing fetus. These bands can constrict a baby's developing fingers, toes, arms, or legs. Rarely, they can wrap around the head, abdomen, or umbilical cord. Amniotic band syndrome occurs in one in every 1,200 to 15,000 births.

Other names for amniotic band syndrome are:

• ADAM sequence
• Amniotic banding
• Amniotic sequence syndrome
• Constriction ring syndrome
• Streeter bands

Causes

Amniotic band syndrome arises from a structural problem with the amniotic sac that develops during pregnancy. The amniotic sac is a fluid-filled bubble inside the uterus in which your baby floats as they grow during your pregnancy.

It's thought that a spontaneous rupture or tearing of the amniotic sac during the first 20 weeks of pregnancy is what causes the amnion, the sac's inner layer, to break and create strands. These strands can stick to and cross over parts of your baby, sort of like rubber bands around a ball, inhibiting growth, blood flow, or both.

Potential Effects

How early these bands develop usually determines how severe the complications will be for your baby. Generally, the earlier these bands begin to grow, the more time a body part is constricted, which is associated with more serious complications. These complications include:

• Abdominal wall disorders
• Cleft lip and/or palate (split in the lip or palate)
• Club hands or club feet (turning inward of the hands or feet)
• Constriction of the umbilical cord (when blood supply to the umbilical cord is cut off, which can be fatal)
• Constriction rings or loss of body parts (fingers, toes, arms, or legs)
• Encephalocele (a neural tube defect in which part of the brain extrudes through the skull)
• Face or skull deformities
• Thoracoschisis (constriction of the thoracic wall)

When amniotic banding develops later, complications are often relatively minor. A baby might have very subtle banding around a finger or toe, for instance. Concerns, if any, are mainly cosmetic.

Risk Factors 

While research points to an early rupturing or tearing of the amniotic sac as the likeliest cause of amniotic band syndrome, scientists are still trying to figure out what puts a pregnant person at risk for such an occurrence.

Some research has pointed to a genetic link, as babies with first-degree relatives with amniotic band syndrome are more likely to have it themselves. There also seems to be a correlation between certain activities and conditions during pregnancy and an increased risk for amniotic band syndrome. These potential risk factors include:

• Smoking in pregnancy
• Drug use in pregnancy
• Misoprostol use (to induce abortion in early pregnancy)
• Amniocentesis (used to determine certain fetal medical conditions between 15 and 20 weeks gestation)
• Maternal diabetes

Diagnosis

When the effects are subtle, amniotic band syndrome is often discovered after a baby is born. However, some cases can be identified during a routine ultrasound during pregnancy.

If your doctor suspects amniotic band syndrome during your pregnancy, they might recommend additional testing to more definitively diagnose the issue. Possible follow-up tests include:

• Anatomy ultrasound: This higher-resolution ultrasound can reveal malformations more clearly and assess blood flow.
• Fetal MRI: An MRI can assess the extent of the complications caused by the amniotic band.
• Fetal echocardiogram: This specialized ultrasound assesses fetal heart function, which can give a doctor clues about your baby's circulation.

Prevention

Currently, there is no clear-cut way to prevent amniotic band syndrome from occurring. However, it's important to talk to your doctor early in your pregnancy if you have a family history of amniotic band syndrome or you have possible risk factors for developing it, like diabetes or if you smoke or use drugs.

Your doctor can give you general recommendations for a healthy pregnancy that may reduce your baby's vulnerability to birth defects in general. This is usually a part of preconception care.

Treatment

There are two potential ways to correct amniotic band syndrome: before birth via fetal surgery and after birth with a variety of surgeries and therapies. In the vast majority of cases, amniotic band syndrome is not treated until after birth.

Fetal Surgery Before Birth

In cases when amniotic banding is constricting the umbilical cord or cutting off the blood supply to a baby's limb, a doctor can attempt to surgically remove the bands before your baby is born. In fetoscopic amniotic band resection, surgeons are guided by ultrasound imagery to use a laser or other surgical instrument to cut the constrictive tissue.

Studies of babies with limbs affected by the condition show that 75% gain functional limbs after fetoscopic amniotic band resection. Since all surgeries carry added risks, this procedure is usually reserved for the most severe cases of amniotic band syndrome.

Surgery and Treatments After Birth

Once babies are born, amniotic banding can be corrected through plastic surgery. Surgeons will release the constrictive tissue and repair the surrounding skin. Unless the constrictive banding is severe enough to pose serious harm to your baby, this procedure is usually done after your child's first birthday.

Sometimes, babies will need occupational therapy to regain strength and coordination in a body part affected by amniotic banding. If a limb is lost as a result of the condition, prosthetics are usually introduced. Because of exciting advances in prosthetics, children can regain full function in these limbs by toddlerhood—as early as 12 to 18 months of age.

A Word From Verywell

Even though amniotic band syndrome is usually well managed through expert observation and helpful treatments, it's natural for parents to experience emotional and even social stress. Because there are not a lot of other infants who have these issues, finding support from parents who are or have been in your situation can be extremely helpful.

Fetal centers that specialize in surgery to treat amniotic band syndrome often host support networks for parents. You can search online for resources, too. There are several active Facebook groups for families of children with amniotic band syndrome and birth defects in general. Sharing knowledge and stories can help you feel connected as well as more empowered during an uncertain time.