1. Department of Obstetrics and Gynecology; Nordland Hospital; Bodø Norway
2. Women's Health and Perinatology Research Group; Department of Clinical Medicine; Faculty of Health Science; University of Tromsø; Tromsø Norway
3. Institute for Laboratory Medicine, Women's and Children's Health; Norwegian University of Technology and Science; Trondheim Norway
4. Department of Obstetrics and Gynecology; University Hospital of North Norway; Tromsø Norway