1. Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility; Northwestern University Feinberg School of Medicine; Chicago Illinois USA
2. Department of Preventive Medicine; Northwestern University; Chicago Illinois USA
3. Division of Endocrinology, Metabolism, and Molecular Medicine, Department of Medicine; Northwestern University Feinberg School of Medicine; Chicago Illinois USA
4. Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park; North Carolina USA