1. Department of Obstetrics and Gynecology; Oulu University Hospital; Oulu Finland
2. PEDEGO Research Unit; University of Oulu; Oulu Finland
3. Department of Obstetrics and Gynecology; University Hospital of Helsinki and University of Helsinki; Helsinki Finland
4. Department of Pediatrics; Oulu University Hospital; Oulu Finland
5. Department of Obstetrics and Gynecology; University Hospital of Turku and University of Turku; Turku Finland