Affiliation: | 1. Department of Obstetrics and Gynecology, St. Antonius Hospital, Nieuwegein, The Netherlands;2. Department of Obstetrics and Gynecology, University Medical Centre Utrecht, The Netherlands;3. Department of Statistics, St. Antonius Hospital, Nieuwegein, The Netherlands;4. Department of Obstetrics and Gynecology, University Medical Centre Groningen, The Netherlands Department of Obstetrics and Gynecology, Academic Medical Centre Amsterdam, The Netherlands |