1. Centre of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer-Campus 1, Building D11, 48149 Münster, Germany
2. Department of Women's and Children's Health, NORDFERTIL Research Lab Stockholm, Paediatric Endocrinology Unit, Q2:08, Karolinska Institutet and Karolinska University Hospital, SE-17176 Stockholm, Sweden
3. Centre of Reproductive Medicine and Andrology, Department of Clinical and Surgical Andrology, Albert-Schweitzer-Campus 1, Building D11, 48149 Münster, Germany