1 Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Utah Health, 30N 1900 East, Room 2B200, Salt Lake City, UT 84132; Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Intermountain Healthcare, Salt Lake City, UT. Electronic address: brett.einerson@hsc.utah.edu.
2 Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Utah Health, Salt Lake City, UT.
3 George Washington University Biostatistics Center, Washington, DC.
4 Division of Epidemiology, Department of Internal Medicine, University of Utah Health, Salt Lake City, UT; IDEAS Center, VA Salt Lake City Healthcare System, Salt Lake City, Utah.
5 Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Utah Health, Salt Lake City, UT; Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Intermountain Healthcare, Salt Lake City, UT.
6 Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Northwestern University, Chicago, IL.