Amniotic Band Syndrome (ABS):A Review

Amniotic Band Syndrome (ABS) is a group of congenital abnormalities caused by bands of amnion (inner lining of the "bag of waters") that attach to the fetus. It is caused by entrapment of fetal parts (usually limb or digits) in fibrous amniotic bands while in utero. The congenital malformations are ranging from minor constriction rings and lymphedema of the digits to complex, bizarre multiple congenital anomalies. The timing of the rupture is believed to occur between 28 days after conception to 18 weeks of gestation. However, late bands can occur and present at birth with multiple abnormalities of the limbs, even after a normal sonogram was performed earlier in gestation.