1. Department of Obstetrics and Gynaecology; VU University Medical Centre; Amsterdam the Netherlands
2. EMGO Institute for Health and Care Research; VU University Medical Centre; Amsterdam the Netherlands
3. Department of Public and Occupational Health; VU University Medical Centre; Amsterdam the Netherlands
4. Research Center for Insurance Medicine; AMC-UMCG-UWV-VUMC; VU University Medical Centre; Amsterdam the Netherlands
5. Department of Epidemiology and Biostatistics; VU University Medical Center; Amsterdam the Netherlands