作者单位:Academic Department of Development and Regeneration, KU Leuven, Belgium[1]Department of Obstetrics and Gynaecology, University Hospital KU Leuven, Herestraat 49, 3000 Leuven[2]Department of Obstetrics and Gynaecology, Queen Charlotte's and Chelsea Hospital, Imperial College[3]Department of Obstetrics and Gynecology, Columbia University, College of Physicians and Surgeons[4]