Discordant anencephaly in a set of triplets.

A 38-year-old woman, gravida 5, para 3, with a triplet pregnancy discordant for anencephaly, is reported. The diagnosis was made prenatally by ultrasound. Autopsy of the anencephalic member revealed small adrenal glands with absent fetal cortex, and a coincidental tetralogy of Fallot. Studies of the histocompatible lymphocyte antigens of both parents were performed and they failed to demonstrate HLA B-27. The literature on anencephaly in triplets is summarized. The association of congenital heart disease and HLA B-27 with anencephaly is discussed.