1. Department of Obstetrics and Gynecology, Haukeland University Hospital, Bergen, Norway;
2. Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway;
3. Department of Internal Medicine, Section of Endocrinology, Haukeland University Hospital, University of Bergen, Bergen, Norway;
4. Department of Pathology, Center for Pediatric and Pregnancy Related Pathology, Oslo University Hospital, Oslo, Norway;
5. Department of Obstetrics and Gynecology, University of Arkansas for Medical Sciences, Little Rock, AR, USA;
6. Department of Obstetrics and Gynecology, University of Mississippi Medical Center, Jackson, MS, USA