[1] Rutgers Robert Wood Johnson Med Sch, Dept Obstet Gynecol & Reprod Sci, Div Maternal Fetal Med, 125 Paterson St, New Brunswick, NJ 08901 USA
[2] Rutgers Robert Wood Johnson Med Sch, Dept Obstet Gynecol & Reprod Sci, New Brunswick, NJ USA
[3] Rutgers Robert Wood Johnson Med Sch, Dept Obstet Gynecol & Reprod Sci, Div Epidemiol & Biostat, New Brunswick, NJ USA
[4] Rutgers Sch Publ Hlth, Dept Biostat & Epidemiol, Piscataway, NJ USA
[5] Rutgers Robert Wood Johnson Med Sch, Environm & Occupat Hlth Sci Inst, Piscataway, NJ USA