1. Department of Medicine, Boston University Chobanian and Avedisian School of Medicine, Boston, MA 02118, USA.
2. Contraception Research Branch, Eunice Kennedy Shriver National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20817, USA.
3. Fertility and Infertility Branch, Eunice Kennedy Shriver National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20817, USA.
4. Gynecologic Health and Disease Branch, Eunice Kennedy Shriver National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20817, USA.