[1] Washington Univ, St Louis Sch Med, Dept Obstet & Gynecol, St Louis, MO USA
[2] Barnes Jewish Hosp, St Louis, MO 63110 USA
[3] Brown Univ, Sch Med, Dept Gen Internal Med, Providence, RI 02912 USA
[4] Brown Univ, Rhode Isl Hosp, Providence, RI 02903 USA
[5] Brown Univ, Sch Med, Pawtucket, RI USA
[6] Brown Univ, Mem Hosp Rhode Isl, Pawtucket, RI 02860 USA