Amniotic band syndrome, or ABS, is a group of congenital disorders that occur when a baby's development is negatively affected by inelastic strings or bands that form inside the womb, explains Children's Memorial Hermann Hospital. The bands restrict blood flow and alter the development of major body parts, particularly the limbs.Continue Reading
When a part of the placenta called the amnion is damaged during pregnancy, it forms amniotic constriction bands, notes MedlinePlus. These bands are tough and fibrous, so as the baby develops, parts of its body become trapped and squeezed by them. The result is ABS.
ABS is a rare condition that is characterized in its mildest forms by creases on a child's body, reports Seattle Children's Hospital. Sometimes ABS does not affect the functioning of the affected body part and no treatment is required. In more severe cases, deformation, nerve damage or even defects in the internal organs can result.
Syndactyly and club foot are two characteristic defects associated with ABS, notes Seattle Children's Hospital. A child with syndactyly has fingers that are fused together into a single digit. Club foot results when the amniotic constriction bands damage the peroneal nerve, the nerve that controls the lower leg and foot.
ABS can also cause cleft lip and cleft palate, adds Children's Memorial Hermann Hospital. Severely tight bands around the arms or legs can cause loss of limbs. If the bands cause damage to the neck or umbilical cord, ABS can be life-threatening.Learn more about Human Anatomy