1. Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School/Robert Wood Johnson University Hospital, New Brunswick, New Jersey, USA
2. Perinatal Institute, Meridian Health System, Jersey Shore Medical Center, Neptune, New Jersey, USA
3. Section of Epidemiology and Biostatistics, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School/Robert Wood Johnson University Hospital, New Brunswick, New Jersey, USA