1. Women’s Clinic, Ghent University Hospital, Corneel Heymanslaan 10, 9000 Ghent, Belgium
2. Centre for Reproductive Medicine, University Hospital Brussels, Laarbeeklaan 101, 1090 Brussels, Belgium
3. Department of Obstetrics and Gynaecology, Leuven University Fertility Centre, University Hospital Leuven, Herestraat 49, 3000 Leuven, Belgium
4. Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Avenue Hippocrate 10, 1200 Brussels, Belgium
5. Département de Gynécologie-Obstétrique, CHU Site, CHR Citadelle, Boulevard du Douzième de Ligne 1, 4000 Liège, Belgium
6. Department of Obstetrics and Gynaecology, Jessa Hospital, Stadsomvaart 11, 3500 Hasselt, Belgium
7. Biostatitics Unit, Department of Public Health and Primary Care, Ghent University, C. Heymanslaan 10, 9000 Gent, Belgium
8. Department of Gynaecology, Imelda Hospital, Imeldalaan 9, 2820 Bonheiden, Belgium