1. Department of Gynecological Endocrinology, Poznan University of Medical Sciences, Poznan, Poland,
2. Students Scientific Association of the Department of Gynecological Endocrinology, Poznan University of Medical Sciences, Poznan, Poland,
3. Department of Gynecological Endocrinology, Warsaw Medical University, Warsaw, Poland, and
4. Department of Reproductive Medicine and Child Development, Division of Gynecology and Obstetrics, University of Pisa, Pisa, Italy