1. Department of Obstetrics and Gynecology; Helsinki University Central Hospital; Helsinki Finland
2. University of Helsinki; Helsinki Finland
3. Department of Clinical Chemistry; University of Eastern Finland; Kuopio Finland
4. Eastern Finland Laboratory Centre; Kuopio Finland
5. Department of Obstetrics and Gynecology; Porvoo Hospital; Porvoo Finland
6. Department of Medical Genetics; Haartman Institute, University of Helsinki; Helsinki Finland
7. Department of Obstetrics and Gynecology; Oulu University Hospital; Oulu Finland
8. Department of Clinical Chemistry; University of Helsinki; Helsinki Finland
9. Department of Obstetrics and Gynecology; Kuopio University Hospital and University of Eastern Finland; Kuopio Finland