Zdenek Rusavy1,2, Vladimir Kalis3,4. 1. Department of Gynecology and Obstetrics, University Hospital and Medical Faculty in Pilsen, Charles University in Prague, Alej Svobody 80, Pilsen, 304 60, Czech Republic. rusavyz@fnplzen.cz. 2. Biomedical Centre, Faculty of Medicine in Plzen, Charles University in Prague, Plzen, Czech Republic. rusavyz@fnplzen.cz. 3. Department of Gynecology and Obstetrics, University Hospital and Medical Faculty in Pilsen, Charles University in Prague, Alej Svobody 80, Pilsen, 304 60, Czech Republic. 4. Biomedical Centre, Faculty of Medicine in Plzen, Charles University in Prague, Plzen, Czech Republic.