1. Department of Obstetrics and Gynecology; South Karelia Central Hospital; Lappeenranta Finland
2. Department of Information; National Institute for Health and Welfare; Helsinki Finland
3. Nordic School of Public Health; Gothenburg Sweden
4. Department of General Practice and Primary Health Care; University of Helsinki; Helsinki Finland
5. Unit of General Practice; Helsinki University Central Hospital; Helsinki Finland
6. Folkhälsan Research Centre; Helsinki, Helsingfors Universitet; Helsinki Finland
7. Department of Chronic Disease Prevention; National Institute for Health and Welfare; Helsinki Finland
8. Department of Obstetrics and Gynecology; Helsinki University Central Hospital; Helsinki Finland