1. Tommy's National Centre for Miscarriage Research, Department of Obstetrics and Gynecology Queen Charlotte's & Chelsea Hospital, Imperial College London Du Cane Road London UK
2. St Mary's Hospital, Department of Obstetrics and Gynecology Imperial College London Praed Street London UK
3. Department of Obstetrics and Gynecology University Hospitals Leuven, Herestraat 49 Leuven Belgium