Amniotic band syndrome is a well-known condition potentially associated with a variety of different birth defects. It is important to note that no two cases of amniotic band syndrome are exactly alike and that the associated symptoms are highly variable. The severity of amniotic band syndrome can range from a single, isolated finding to multiple, disfiguring complications. The arms and legs are most often affected. The head and face and, in some cases, various internal organs can also be affected. The exact cause of amniotic band syndrome is unknown and controversial. Two main theories have been proposed to explain the development of the disorder. One theory attributes the disorder to causes that arise internally within the fetus (intrinsic theory); the other theory attributes the disorder to causes acting upon the fetus externally (extrinsic theory). It is likely that both internal and external factors can cause amniotic band syndrome, and that the cause of the disorder in one infant may be different from the cause in another infant.