Ovarian hilar cells and testicular Leydig cells in anencephaly.

The presence of ovarian hilar cells in anencephaly has been investigated and compared with the presence of testicular Leydig cells in the same condition. The examination of 29 anencephalic ovaries and 49 controls showed that up to 36 weeks of gestation there was a preponderance of ovarian hilar cells in anencephalic monsters as compared with controls. Similar observations were made with regard to ovarian follicles which showed more pronounced maturational changes than controls. However, during the last month of gestation both these processes were more marked in the controls. These findings are in marked contrast to our previous observations on the testes in anencephalic monsters which showed significantly less Leydig cells than controls throughout the third trimester of pregnancy. It is assumed that these appearances are due to the fact that testes and ovaries are not strictly comparable structures and may, therefore, react in a different way to hormonal stimulation. This is of particular interest as the placental chorionic gonadotrophin levels which stimulate the development of testicular Leydig cells and, supposedly, the development of ovarian hilar cells are normal in anencephaly.