1. The Fertility Clinic, Department of Obstetrics and Gynaecology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
2. Fertility Clinic, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
3. Section of Biostatistics, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
4. The Fertility Clinic, Department of Obstetrics and Gynaecology, Herlev University Hospital, Copenhagen, Denmark
5. The Fertility Clinic, Department of Obstetrics and Gynaecology, Zealand University Hospital, Køge
6. The Fertility Clinic, Skive Regional Hospital and Faculty of Health, Aarhus University, Aarhus, Denmark
7. Department of Obstetrics and Gynaecology, Institute of Clinical Sciences, Gothenburg University, Reproductive Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden