1. Division of Neonatology and Developmental Medicine, Department of Pediatrics Stanford University School of Medicine Stanford California USA
2. Division of Maternal‐Fetal Medicine and Obstetrics, Department of Obstetrics and Gynecology Stanford University School of Medicine Stanford California USA
3. Department of Epidemiology, Gillings School of Global Public Health University of North Carolina Chapel Hill North Carolina USA
4. Department of Epidemiology and Arkansas Center for Birth Defects Research and Prevention, Fay W. Boozman College of Public Health University of Arkansas for Medical Sciences Little Rock Arkansas USA
5. Division of Cardiology, Department of Pediatrics University of Kentucky College of Medicine Lexington Kentucky USA
6. Center for Birth Defects Research and Prevention Massachusetts Department of Public Health Boston Massachusetts USA