1. Women′s Health and Perinatology Research Group Department of Clinical Medicine UiT – The Arctic University of Norway Tromsø Norway
2. Homerton Fertility Center Homerton University Hospital London UK
3. Center for Reproductive Medicine St Bartholomew's Hospital London UK
4. Division of Obstetrics and Gynecology Department of Clinical Science, Intervention and Technology Karolinska Institutet and Center for Fetal Medicine Karolinska University Hospital Stockholm Sweden