1. Center for Clinical Research Sörmland Uppsala University Eskilstuna Sweden
2. Department of Women's and Children's Health Uppsala University Uppsala Sweden
3. Department of Obstetrics and Gynecology Institute of Clinical Science, Sahlgrenska Academy, University of Gothenburg Gothenburg Sweden
4. Department of Obstetrics and Gynecology Stellenbosch University Stellenbosch South Africa
5. Center for Clinical Research Dalarna Falun Sweden