1. Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, California
2. Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Women and Infants Hospital of Rhode Island, The Warren Alpert Medical School of Brown University, Providence, Rhode Island
3. Division of Maternal-Fetal Medicine, Methodisth Women's Hospital and Perinatal Center, Omaha, Nebraska