1. Department of Epidemiology Care and Public Health Research Institute (CAPHRI) Maastricht University Maastricht The Netherlands
2. Department of Obstetrics and Gynecology School for Oncology and Developmental Biology (GROW)Maastricht University Medical CenterMaastricht The Netherlands
3. Department of Obstetrics and Gynecology Sint Jans Gasthuis Weert The Netherlands
4. Department of Obstetrics and Gynecology Zuyderland Medical Center Heerlen The Netherlands
5. Department of Obstetrics and Gynecology Laurentius Hospital Roermond The Netherlands