[1] Katholieke Univ Leuven, Leuven, Vlaams Brabant, Belgium
[2] UZ Leuven, Leuven, Belgium
[3] Leiden Univ, Med Ctr, The Hague, Zuid Holland, Netherlands
[4] Leiden Univ, Med Ctr, Leiden, Netherlands
[5] Karolinska Univ Hosp, Stockholms Lan, Netherlands
[6] Univ Hosp Leuven, Dept Obstet & Gynaecol, Leuven, Vlaams Brabant, Belgium