1. Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
2. Department of Environmental Health Sciences, and
3. Department of Biostatistics, University of Michigan School of Public Health, Ann Arbor, Michigan, USA
4. Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA