Institution: | 1. Department of Pathology, Pennsylvania Hospital, and Department of Obstetrics and Gynecology†, Medical College of Pennsylvania, Philadelphia, Pennsylvania, U.S.A.;2. Department of Obstetrics and Gynecology, Medical College of Pennsylvania, Philadelphia, Pennsylvania, U.S.A;3. Maternal-Fetal Medicine, Medical College of Pennsylvania, Philadelphia, Pennsylvania, U.S.A. |