Affiliation: | 1. Division of Maternal and Fetal Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA;2. Department of Obstetrics and Gynecology, Center for Research on Reproduction and Women's Health, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA;3. Division of Maternal and Fetal Medicine and Reproductive Genetics, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA |