1. Department of Obstetrics and Gynecology, Columbia University College of Physicians and Surgeons, New York, USA
2. Herbert Irving Comprehensive Cancer Center, Columbia University College of Physicians and Surgeons, New York, New York, USA
3. New York Presbyterian Hospital, New York, New York, USA
4. Department of Epidemiology, Joseph L. Mailman School of Public Health, Columbia University, New York, New York, USA
5. Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA