Children's Hospital Colorado

Amniotic Band Syndrome

Amniotic band syndrome (ABS) occurs when the amnion, one of two layers that form the amniotic sac, tears or is damaged. This may cause bands to form, which can attach and tighten around any part of a developing baby, including the umbilical cord. These amniotic bands can disrupt development and put the baby at risk.

The Colorado Fetal Care Center is here for moms and babies experiencing difficulties related to amniotic band syndrome. We know that early diagnosis and quick treatment are the best ways to prevent complications from ABS. That's why our team of multidisciplinary fetal specialists are here to support you and your family.

Learning that your baby has amniotic band constriction can be overwhelming. The Colorado Fetal Care Center is a national leader in diagnosing and treating this syndrome, so we'll be with you every step of the way.

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:

  • Clubfoot
  • Stunted growth of fingers and toes
  • Webbed toes or fingers
  • Cleft palate

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.

But there is good news! 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.

The Colorado Fetal Care Center 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 the Colorado Fetal Care Center 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.

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