1 Department of Obstetrics and Gynecology University of Texas Medical Branch at Galveston Galveston, Texas Department of Obstetrics and Gynecology Thomas Jefferson University Jefferson Medical College Philadelphia, Pennsylvania Department of Obstetrics and Gynecology Case Western Reserve University Cleveland, Ohio Department of Obstetrics and Gynecology Women and Infants Hospital of Rhode Island Providence, Rhode Island Eunice Kennedy Shriver National Institute of Child Health and Human Development National Institutes of Health Bethesda, Maryland.