1 Department of Obstetrics and Gynecology, University-Hospital Tuebingen, Calwerstrasse 6, 72076, Tuebingen, Germany. christl.reisenauer@med.uni-tuebingen.de.
2 Department of Obstetrics and Gynecology, University-Hospital Tuebingen, Calwerstrasse 6, 72076, Tuebingen, Germany.