[1] CHU Res Ctr, Quebec City, PQ G1V 4G2, Canada
[2] Univ Laval, Fac Med, Dept Obstet & Gynecol, Ctr Rech & Biol Reprod, Quebec City, PQ G1V 0A6, Canada
[3] Univ Helsinki, Dept Obstet & Gynecol, FI-00014 Helsinki, Finland
[4] Univ Helsinki, Womens Hlth Res Program, FI-00014 Helsinki, Finland
[5] Univ Helsinki, Childrens Hosp & Womens Hlth Res Program, FI-00014 Helsinki, Finland
[6] Washington Univ, Dept Pediat, St Louis, MO 63110 USA
[7] St Louis Childrens Hosp, St Louis, MO 63110 USA