作者单位:Department of Obstetrics and Gynecology, University of Ulm, Prittwitzstrasse 43, 89075 Ulm, Germany[1]Department of Obstetrics and Gynecology, Klinikum Traunstein, Cuno-Niggl-Str. 3, 83278 Traunstein[2]Department of Obstetrics and Gynecology, Campus Innenstadt, Ludwig-Maximilians University[3]