1. Division of Epidemiology; Department of Environmental Health; University of Cincinnati College of Medicine; Cincinnati OH
2. Department of Epidemiology and Social Science on Reproductive Health; Shanghai Institute of Planned Parenthood Research; Shanghai China
3. Division of Maternal-Fetal Medicine; Department of Obstetrics and Gynecology; University of Cincinnati College of Medicine and Perinatal Institute; Cincinnati Children's Hospital Medical Center; Cincinnati OH