1. Nuffield Department of Women's & Reproductive Health, University of Oxford, Level 3, Women's Centre, John Radcliffe Hospital, OX3 9DU, Oxford, UK
2. Nuffield Department of Orthopaedics, The Kennedy Institute of Rheumatology, Rheumatology & Musculoskeletal Sciences, University of Oxford, Roosevelt Drive, Headington, OX3 7FY, Oxford, UK
3. Department of Biology, Biotechnology of Animal & Human Reproduction (TechnoSperm), Unit of Cell Biology, Institute of Food & Agricultural Technology, University of Girona, E-17003, Girona, Spain