1. Department of Obstetrics, Division of Maternal-Fetal Medicine, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductive Medicine, St. Petersburg, Russia;
2. Department of Obstetrics, Gynecology and Reproduction, Faculty of Medicine, St. Petersburg State University, St. Petersburg, Russia;
3. Department of Genetics, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductive Medicine, St. Petersburg, Russia