1. Department of Mother and Child Health, Poznan University of Medical Sciences, 33 Polna Street, 60-535 Poznan, Poland
2. Chair of Obstetrics Development, Faculty of Health Sciences, Medical University of Lublin, 4/6 Staszica Street, 20-081 Lublin, Poland
3. University Clinical Hospital in Poznan, 49 Przybyszewskiego Street, 60-355 Poznan, Poland