[1] North Shore Univ Hosp, Dept Obstet & Gynecol, Manhasset, NY USA
[2] Long Isl Jewish Med Ctr, Manhasset, NY USA
[3] George Washington Univ, Dept Obstet & Gynecol, Sch Med & Hlth Sci, Washington, DC 20037 USA
[4] George Washington Univ, Sch Med & Hlth Sci, Washington, DC 20052 USA
[5] Univ N Carolina, Dept Obstet & Gynecol, Sch Med, Chapel Hill, NC USA
[6] George Washington Univ, Dept Orthoped Surg, Sch Med & Hlth Sci, Washington, DC 20037 USA