Amniotic Rupture, Extra-Amniotic Pregnancy, and Vernix Granulomata

Amniotic rupture is a rare condition observed thus far only in cases of extra-amniotic pregnancy. In examples previously reported, the ruptured membranes were small, and the diagnosis was unequivocal in each instance. When the membrane is large, the placental changes can be overlooked, especially when the infant does not have the amniotic band syndrome. The present authors have observed two such placentas from otherwise normal pregnancies. The presence of vernix granulomata in the denuded chorionic mesenchyme of both placentas confirmed the diagnosis of antepartum amniotic rupture.Case 1. A 25-year-old woman, gravida 2, para 1, delivered a set of fraternal twins after 31.5 weeks of gestation. The course of pregnancy was uneventful, and she denied taking any medication. There was no documented history of trauma or premature rupture of membranes. Labor commenced spontaneously and lasted 5/2 hours before the first twin, a 1740-gm male, was delivered vaginally after rupture of the bulging amniotic sac. No oligohydramnios was noted. The second amniotic sac ruptured 15 minutes later, and a 1810-gm female was delivered. Both twins were free of malformations, including those of the amniotic band syndrome. The first twin developed hyper-bilirubinemia and was found later to have hyperthyroidism; the second developed hyaline membrane disease and hyperbilirubinemia. Both infants were treated successfully and discharged in satisfactory condition at age 23 days.