1. Division of Epidemiology, Statistics and Prevention Research, Eunice Kennedy Shriver National Institute of Child Health and Human Health, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland, USA
2. Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, Utah, USA
3. Department of Obstetrics, Gynecology and Reproductive Sciences, University of California–San Francisco, San Francisco, California, USA
4. Department of Family and Preventive Medicine, and
5. Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, Utah, USA
6. Division of Environmental Health Sciences, Wadsworth Center, New York State Department of Health, and the Department of Environmental Health Sciences, University at Albany, State University of New York, Albany, New York, USA