1. Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, McGovern Medical School, UTHealth, The University of Texas Health Science Center at Houston, Houston, Texas
2. The Fetal Center, Children's Memorial Hermann Hospital, Houston, Texas
3. Department of Epidemiology and Biostatistics, The George Washington University Biostatistics Center, Milken Institute School of Public Health, George Washington University, Rockville, Maryland
4. Department of Reproductive Biology, Case Western Reserve University School of Medicine, Cleveland, Ohio