1. Department of Obstetrics and Gynaecology Amsterdam Reproduction & Development Amsterdam UMC Vrije Universiteit Amsterdam Amsterdam the Netherlands
2. Department of Obstetrics and Gynaecology Deventer Hospital Deventer the Netherlands
3. Department of Health Sciences Amsterdam Public Health Faculty of Science Vrije Universiteit Amsterdam Amsterdam the Netherlands
4. Department of Obstetrics and Gynaecology Amsterdam Reproduction & Development Amsterdam UMC Universiteit van Amsterdam Amsterdam the Netherlands
5. Department of Epidemiology and Biostatistics Amsterdam UMC Vrije Universiteit Amsterdam Amsterdam the Netherlands
6. Department of Obstetrics and Gynaecology Máxima Medical Centre Research School Grow Maastricht University Veldhoven the Netherlands