Amniotic Band Syndrome
What is amniotic band syndrome?
Amniotic band syndrome, or ABS, refers to a condition caused by damage to the amnion, the sac that surrounds the baby while they are in the womb. When this sac is damaged, fibrous strings or bands can enter the amniotic fluid. Occasionally, these bands may wrap around parts of a baby's body, hindering blood flow and growth.
In most cases of ABS, amniotic bands wrap around the arms, fingers, legs or toes. Some rare cases involve the head or waist of a baby. Damage to the amnion can occur early in pregnancy development (between 6 and 18 weeks of pregnancy) or after a fetal procedure. The earlier the bands form, the more likely it is for these bands to result in serious complications. Current studies estimate that ABS occurs in approximately 1 out of every 1,200 live births.
At Children’s Hospital Colorado, our Colorado Fetal Care Center is one of the country’s top centers for diagnosing and treating ABS.
What causes amniotic band syndrome?
Amniotic band syndrome usually occurs when fibrous bands enter the uterus following a partial rupture (break) of amnion. This can occur spontaneously early in pregnancy or, rarely, after a fetal procedure.
ABS is considered a sporadic event or a spontaneous accident that occurs during early development of the amnion, placenta and fetus. This means there is no known cause. The condition is not inherited and there is no increased risk of this condition happening again in a future pregnancy.
What are the signs and symptoms of amniotic band syndrome?
Amniotic band signs and symptoms vary depending on when the damage to the amniotic sac occurs. They also depend on which of the baby's body parts are constricted by the amniotic bands. The mother usually has no signs or symptoms and the diagnosis occurs incidentally during an ultrasound of the fetus.
What are the complications of ABS?
Amniotic bands, when wrapped around your baby's body parts, can cause 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 things, 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
Women with amniotic band syndrome may experience a condition called preterm premature rupture of membranes (PROM) early in pregnancy and have their baby early – at 32 weeks on average. PROM is a condition in which the amniotic sac breaks early.
What tests are used to diagnose amniotic band syndrome?
Because women don’t have symptoms, doctors typically diagnose ABS during an ultrasound. Pediatric experts at the Colorado Fetal Care Center can perform a detailed examination of the fetus by ultrasound and fetal MRI, and in some cases may be able to provide treatment.
What to expect from tests used to diagnose amniotic band syndrome
A detailed initial ultrasound exam of the fetus takes about 30 to 45 minutes. An MRI takes about 1 hour.
How do we diagnose amniotic band syndrome?
Most amniotic bands are found during routine ultrasound between 6 and 18 weeks of pregnancy. If the fetus is affected by the bands, a type of ultrasound referred to as color Doppler can be used to assess the status of the blood flow where the band is attached. Depending on the severity of the case as seen by ultrasound, we may recommend an MRI to obtain additional information. If we see a band on your baby’s ultrasound, this does not automatically mean that your baby has suffered damage.
If we find that you have ABS, our team of fetal care specialists will create a care plan tailored to you and your baby's specific case. Sometimes, fetal surgery (surgery while your baby is in the womb) is recommended to prevent or decrease complications from amniotic bands. In cases of ABS that do not threaten life or limb, surgery after your baby is born might minimize or reverse any birth defects caused by ABS once your baby is born.
How is amniotic band syndrome treated?
Our providers tailor amniotic band syndrome treatment to your baby’s specific needs. Amniotic band syndrome is often treated after birth with surgery to repair defects, but sometimes fetal surgery may be required.
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 a fetal procedure with a fetoscope (a small telescope) to free the baby from the bands. This is called a fetoscopy. Additionally, fetal surgery for ABS can save a limb if the baby is at risk of losing it.
Surgery after birth
When a baby is born with birth defects caused by band constriction, our surgeons can perform reconstructive surgeries to repair cleft palate or cleft lips, webbed feet or fingers, or other body parts damaged by constrictive bands.
Why choose us for treatment of amniotic band syndrome?
The Colorado Fetal Care Center at Children’s Colorado 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 of experience providing care for expectant families.