1. G. A. Ushakova Department of Obstetrics and Gynecology, Kemerovo State Medical University, Kemerovo, Russia
2. Obstetrics and Gynecology Department, Chita State Medical Academy, Chita, Russia
3. Department of Obstetrics and Gynecology, A.I. Evdokimov Moscow State University of Medicine and Dentistry, Moscow, Russia