1. Department of Development and Regeneration, Organ Systems, KU Leuven, 3000 Leuven, Belgium
2. Department of Obstetrics and Gynaecology, Leuven University Fertility Centre, University Hospital Leuven, 3000 Leuven, Belgium
3. Departments of Obstetrics and Gynecology and Clinical Investigation, Madigan Healthcare System, Tacoma, WA 98431, USA
4. Division of Reproductive Biology, Institute of Primate Research, Karen, Nairobi 00 100, Kenya
5. Department of Obstetrics and Gynecology, University of California San Francisco, San Francisco, CA 94015, USA