Prenatal exposure to anticonvulsants and psychosexual development

Animal studies have shown that prenatal exposure to the anticonvulsant drug s phenobarbital and phenytoin alters steroid hormone levels which consequen tly leads to disturbed sexual differentiation. In this study, possible sequ elae of prenatal exposure to these anticonvulsants on gender development in humans were investigated. A follow-up study was carried out in phenobarbit al- and phenytoin-exposed subjects and control subjects matched for age, se x and the mothers' ages. Subjects were born in the Academic Medical Center between 1957 and 1972. Out of 243 exposed and 222 control subjects who were asked to volunteer 147 exposed subjects (72 male, 75 female) and equal num bers of their matched control subjects participated in the follow-up study. They were interviewed and were asked to fill out questionnaires on gender role behavior gender development and sexual orientation. As a group, expose d and control subjects did not differ with respect to gender role behavior although higher numbers of prenatally anticonvulsant-exposed subjects repor ted current or past cross-gender behavior and/or gender dysphoria. Three pr enatally anticonvulsant-exposed subjects were transsexuals and had undergon e sex reassignment surgery a remarkably high rate given the rarity of trans sexualism. In addition, two exposed males had exclusively homosexual experi ences, whereas none of the control males reported exclusive homosexual beha vior The groups did not differ in attainment of pubertal psychosexual miles tones.