1. Clinical Research Unit, Department of Obstetrics & Gynecology, Klinikum rechts der Isar, Technische Universitaet Muenchen, Germany
2. University of Copenhagen, Faculty of Life Sciences, Department of Veterinary Disease Biology, Ridebanevej 9, DK-1870 Frederiksberg C, Denmark
3. Clinical Research Unit, Department of Obstetrics & Gynecology, Ismaninger Strasse 22, Klinikum rechts der Isar, Technische Universitaet Muenchen, D-81675 Munich, Germany.