Affiliation: | 1. Department of Gynaecology, University Medical Center Groningen, University of Groningen, Netherlands;2. Department of Epidemiology, University Medical Center Groningen, University of Groningen, Netherlands;3. Department of Obstetrics and Gynaecology, Isala Clinics Zwolle, Netherlands;4. Department of Obstetrics and Gynaecology, Hospital Group Twente Hengelo, Netherlands;5. Department of Obstetrics and Gynaecology, Wilhelmina Hospital Assen, Netherlands;6. Department of Obstetrics and Gynaecology, Martini Hospital Groningen, Netherlands;7. Department of Obstetrics and Gynaecology, Máxima Medical Centre Veldhoven, Netherlands |