1. Department of Gynecological Endocrinology, University of Medical Sciences of Poznań, Poznań, Poland;
2. Department of Obstetrics and Gynecology, University Hospital of Geneva, Geneva, Switzerland;
3. Department of Operative Gynecology, University of Medical Sciences of Poznań, Poznań, Poland;
4. Department of Obstetrics and Gynecology, University of Pisa, Pisa, Italy;
5. Centre of Reproductive Medicine, University Hospital Brussels, Brussels, Belgium