1 Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Medical College of Wisconsin, Milwaukee.
2 Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Women & Infants Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island.
3 Department of Emergency Medicine, Pediatrics, and Health Services, Policy and Practice Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence.
4 Brown University School of Public Health, Providence, Rhode Island.