[1] Univ Med Ctr Utrecht, Dept Obstet & Gynaecol, NL-3508 AB Utrecht, Netherlands
[2] Onze Lieve Vrouw Hosp, Dept Obstet & Gynaecol, Amsterdam, Netherlands
[3] St Antonius Hosp, Dept Obstet & Gynaecol, Nieuwegein, Netherlands
[4] Vrije Univ Amsterdam Med Ctr, Dept Obstet & Gynaecol, Amsterdam, Netherlands
[5] Jeroen Bosch Hosp, Dept Obstet & Gynaecol, Shertogenbosch, Netherlands
[6] Amsterdam Med Ctr, Dept Obstet & Gynaecol, Amsterdam, Netherlands
[7] Univ Med Ctr Utrecht, Dept Epidemiol, Julius Ctr Hlth Sci & Primary Care, NL-3508 AB Utrecht, Netherlands
[8] Maxima Med Ctr, Dept Obstet & Gynaecol, Veldhoven, Netherlands
[9] TweeSteden Hosp, Dept Obstet & Gynaecol, Tilburg, Netherlands
[10] Diakonessen Hosp, Dept Obstet & Gynaecol, Utrecht, Netherlands
[11] Maastricht Univ, Dept Obstet & Gynaecol, Med Ctr, Maastricht, Netherlands