Children's Hospital Colorado

Amniotic Band Syndrome

What is amniotic band syndrome?

Amniotic band syndrome, or ABS, refers to conditions caused by damage to the amnion, the sac surrounding a fetus in utero. When this sac is partially disrupted, fibrous strings or bands can enter the amniotic fluid and wrap around parts of a baby's body, hindering growth.

In most cases, amniotic bands wrap around the arms, legs or fingers and toes. Some rare cases involve the head or waist of a baby. The disruption in the amnion can occur anytime between 6 and 18 weeks of pregnancy. The earlier the bands form, the more likely it is for these bands to result in serious complications.

What causes amniotic band syndrome?

Current studies estimate that ABS occurs in approximately 1 out of every 1,200 live births. This syndrome is caused by fibrous strands or bands entering the uterus and wrapping around parts of a baby's body. As the baby grows, the bands tighten and constrict growth and blood flow. The bands usually enter the uterus due to a partial rupture of amnion, the sac surrounding the baby.

There is no increased risk of this condition happening again in a future pregnancy.

The signs of ABS vary depending on when the damage to the amniotic sac occurs, as well as which of the baby's body parts are constricted by the amniotic bands.

What are the complications of ABS?

Amniotic bands, when wrapped around your baby's body parts, can cause limb deformities such as:

In the most severe cases, amniotic bands cause organ damage or loss of pregnancy.

What is the long-term outcome for babies with amniotic band syndrome?

The outcome depends on many variables, including:

  • Timing of the amnion's rupture during pregnancy
  • Location of the band constriction
  • If and when the condition is diagnosed (usually through an ultrasound or at birth)
  • The severity of the damage caused by band constriction

All cases of amniotic band syndrome have PPOROM (Preterm Premature Rupture of Membranes) and the average gestational age delivery is 32 weeks. Early diagnosis at specialist clinics like the Colorado Fetal Care Center can potentially save a baby's life or limbs.

How is ABS diagnosed in utero?

Most amniotic bands are found during routine ultrasound between 6 and 18 weeks of pregnancy. However, if a band is visualized on ultrasound, it does not automatically mean that your baby has suffered damage.

If ABS is diagnosed, the team at the Colorado Fetal Care Center gets to work creating a care plan tailored to your baby's specific case. Sometimes, prenatal surgery is recommended to prevent or decrease complications from amniotic bands. In cases of ABS that do not threaten life or limb, postnatal surgery might minimize or reverse the effects of birth defects once a baby is born.

ABS treatment at the Colorado Fetal Care Center

Our team tailors the treatment of amniotic band syndrome to your child's specific needs. Amniotic band syndrome is often treated after birth with surgery to repair defects, but sometimes fetal surgery may be required.

Fetoscopic surgery

When an amniotic band endangers a baby's life by constricting growth of critical internal organs or threatening the umbilical cord, our specialized surgeons perform an in utero procedure to free the baby from the bands. Additionally, fetal surgery for ABS can save a limb if the baby is at risk of losing it.

Surgery after birth

When babies are born with birth defects caused by band constriction, surgeons can perform reconstructive surgeries to repair cleft palates or cleft lips, webbed feet or fingers or other body parts damaged by constrictive bands.

Why choose us to treat your baby's ABS?

The Colorado Fetal Care Center is one of the nation's top care centers for the treatment of amniotic band syndrome. We have successfully performed surgeries on babies ranging from 16 to 27 weeks' gestation and have a committed fetal surgery team with many years' experience providing care for expectant families.

Related departments