1. Department of Obstetrics and Gynecology Amsterdam Reproduction and Development Research Institute, Amsterdam UMC, University of Amsterdam Amsterdam the Netherlands
2. Department of Clinical Epidemiology, Biostatistics and Bioinformatics Amsterdam University Medical Centers, University of Amsterdam Amsterdam the Netherlands
3. Pregnancy Sickness Support Bodmin UK
4. Department of Obstetrics and Gynecology Noordwest Ziekenhuisgroep Alkmaar the Netherlands
5. Laboratory of Reproductive Biology Amsterdam University Medical Centers, University of Amsterdam Amsterdam the Netherlands
6. Department of Obstetrics and Gynecology Reinier de Graaf Hospital Delft the Netherlands
7. Department of Obstetrics and Gynecology Martini Hospital Groningen the Netherlands
8. Department of Obstetrics and Gynecology Radboud University Medical Center Nijmegen the Netherlands
9. Department of Obstetrics and Gynecology Gelre Hospital Apeldoorn the Netherlands
10. Department of Obstetrics and Gynecology Flevo Hospital Almere the Netherlands
11. Department of Obstetrics and Gynecology Catharina Hospital Eindhoven the Netherlands
12. Department of Obstetrics and Gynecology Máxima Medical Center Veldhoven the Netherlands
13. Department of Obstetrics and Gynecology Zuyderland Hospital Heerlen the Netherlands
14. Department of Obstetrics and Gynecology Franciscus Gasthuis Rotterdam the Netherlands
15. Department of Obstetrics and Gynecology Amphia Hospital Breda the Netherlands
16. Department of Obstetrics and Gynecology Scheper Hospital Emmen the Netherlands
17. Department of Obstetrics and Gynecology Spaarne Gasthuis Haarlem the Netherlands
18. Department of Obstetrics and Gynecology OLVG Amsterdam the Netherlands
19. Department of Obstetrics and Gynecology Jeroen Bosch Hospital 's‐Hertogenbosch the Netherlands
20. Department of Obstetrics and Gynecology Maastricht University Medical Center Maastricht the Netherlands
21. Department of Obstetrics and Gynecology Diakonessenhuis Utrecht the Netherlands
22. Department of Obstetrics and Gynecology Monash University Clayton Victoria Australia