1. Department of Obstetrics and Gynecology, Clinical Research Center, Eastern Virginia Medical School, Norfolk, Virginia.
2. Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, Pennsylvania.
3. Pfizer, Inc., Collegeville, Pennsylvania.
4. Pfizer, Inc., New York, New York.
5. Department of Obstetrics and Gynecology, University of Virginia Health System, Charlottesville, Virginia.