1. Department of Epidemiology, Care and Public Health Research Institute (CAPHRI) Maastricht University Maastricht the Netherlands
2. Department of Clinical Epidemiology and Medical Technology Assessment (KEMTA) Maastricht University Medical Centre Maastricht the Netherlands
3. Department of Obstetrics and Gynaecology Zuyderland Medical Centre Heerlen the Netherlands
4. Department of Obstetrics and Gynaecology Sint Jans Gasthuis Weert Weert the Netherlands
5. Department of Obstetrics and Gynaecology Laurentius Hospital Roermond the Netherlands
6. Department of Obstetrics and Gynaecology School for Oncology and Developmental Biology (GROW) Maastricht University Medical Centre Maastricht the Netherlands