[1] Univ Groningen, Univ Med Ctr Groningen, Dept Obstet & Gynecol, Groningen, Netherlands
[2] Univ Groningen, Univ Med Ctr Groningen, Dept Epidemiol, Groningen, Netherlands
[3] Univ Amsterdam, Amsterdam Univ Med Ctr, Dept Obstet & Gynecol, Amsterdam, Netherlands
[4] Leiden Univ, Med Ctr, Dept Obstet & Gynecol, Leiden, Netherlands
[5] Ikazia Hosp, Dept Obstet & Gynecol, Rotterdam, Netherlands
[6] Amsterdam Reprod & Dev Res Inst, Amsterdam, Netherlands
[7] Univ Med Ctr Groningen, Dept Obstet & Gynecol, Hanzepl 1, NL-9713 GZ Groningen, Netherlands