1. Department of Obstetrics and Gynecology, Medical Center, University of Freiburg, Freiburg, Germany
2. Faculty of Medicine, University of Freiburg, Freiburg, Germany
3. Institute of Veterinary Medicine, Georg-August-University Goettingen, Goettingen, Germany
4. Institute of Genetic Epidemiology, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
5. Department of Gynecology and Obstetrics, Hospital Memmingen, Memmingen, Germany