1. Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Boston, MA, USA
2. Department of Obstetrics, Gynecology and Reproductive Biology, Harvard Medical School, Boston, MA, USA
3. Department of Obstetrics and Gynecology, Warren Alpert Medical School, Brown University, Providence, RI, USA
4. Brown University School of Public Health, Providence, RI, USA