1. Department of Obstetrics and Gynaecology, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands;
2. Department of Obstetrics and Gynaecology, Maxima Medical Centre, Eindhoven, The Netherlands;
3. Department of Obstetrics and Gynaecology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands