ABSTRACT
Amniotic bands occur as a consequence of a disruption to the amnion, with an intact chorion. In most cases, amniotic bands occur without any associated fetal effects, although occasionally a diagnosis of amniotic band syndrome may be made. Amniotic band syndrome is believed to be caused by the entrapment of fetal parts (usually a limb or digits) in fibrous amniotic bands while in utero. When the amnion ruptures without injury to the chorion, the fetus comes in contact with free-floating sticky amniotic ‘bands’. The amniotic bands can entangle various fetal parts, thereby reducing the blood supply and causing congenital abnormalities, typically amputations. Although no two cases are exactly alike, there are several features that are relatively common: syndactyly, distal ring constrictions, shortened bone growth, limb length discrepancy, distal lymphoedema, and congenital bands. Very confusingly, by the time amniotic band syndrome is suspected, the amniotic bands are no longer visible, as the fetal insult probably occurred early in the first trimester.
