1. Division of Obstetrics and Gynecology; Department of Women's and Children's Health; Karolinska Institute; Karolinska University Hospital Solna; Stockholm Sweden
2. CLINTEC; Karolinska Institute and Stockholm IVF; Stockholm Sweden
3. Department of Obstetrics and Gynecology; Institute for Clinical Research; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
4. Ultragyn; Stockholm Sweden
5. Department of Obstetrics and Gynecology; Skåne University Hospital; Lund Sweden
6. Karolinska University Hospital Huddinge; Stockholm Sweden