1. Department of Gynecology, Obstetrics and Gynecological Oncology, Division of Infertility and Reproductive Endocrinology, Poznan University of Medical Sciences, 60‑535 Poznan, Poland
2. Department of Anatomy, Poznan University of Medical Sciences, 60‑781 Poznań, Poland
3. Department of Histology and Embryology, Poznan University of Medical Sciences, 60‑781 Poznań, Poland
4. Department of Obstetrics and Gynecology, University Hospital and Masaryk University, 62500 Brno, Czech Republic
5. Department of Human Morphology and Embryology, Division of Histology and Embryology, Wroclaw Medical University, 50‑368 Wroclaw, Poland