1. Department of Women's and Children's Health; Uppsala University; Uppsala Sweden
2. Center for Clinical Research; Hospital of Västmanland Västerås; Region Västmanland - Uppsala University; Västerås Sweden
3. Center for Pharmacoepidemiology; Department of Medicine; Karolinska Institute; Solna Sweden
4. Department of Obstetrics and Gynecology; Herlev University Hospital; University of Copenhagen; Herlev Denmark