1. Department of Obstetrics and Gynaecology, Academic Medical Center, P.O. Box 22700, 1100 DE Amsterdam, Netherlands
2. Department of Medical Informatics, Academic Medical Center, Amsterdam, Netherlands
3. Department of Obstetrics and Gynaecology, VU University Medical Center, Amsterdam, Netherlands
4. Department of Obstetrics and Gynaecology, Leiden University Medical Center, Leiden, Netherlands
5. School of Paediatrics and Reproductive Health, University of Adelaide, SA 5000, Australia