1. From the Department of Obstetrics and Gynecology, Cedars-Sinai Medical Center, Los Angeles, CA (R.M.B., M.G.)
2. Department of Obstetrics and Gynecology, Oregon Health and Science University, Portland (M.R., S.S.B.)
3. Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, NY (B.B.F.).