Neural tube defect and amniotic band sequence.

A 28-years-old pregnant woman was examined by fetal ultrasonography at 18 weeks' gestation. Anencephaly was diagnosed, followed by prostaglandin induced abortion and fetotomy. Fetal fragments showed a very small head, bilateral anophthalmy, absence of nasal structures and calvarium, intact cranial skin and a very small cranial cavity. The right lower limb was reduced to a few toes covered by a large amniotic adhesion. The left lower limb showed an amniotic band from sole to thigh. The abdominal wall was absent. The diagnoses were amniotic adhesion syndrome and cephalic pole induction failure. The pathogenesis of these defects has been the subject of controversy. Vascular disruption and secondary reduction of the paraaxial mesodermal cells can explain the anomalies observed in this case.