From the Department of Obstetrics and Gynecology, Yale University School of Medicine, New Haven, Conn.

Supported in part by Grants HE 09507–02 from the National Heart Institute and HD 01467–02 from the National Institute of Child Health and Human Development, U. S. Public Health Service.

^* Present address: Portsmouth Naval Hospital, Portsmouth, Va. (serving as LCDR, USNR).