1. Department of Obstetrics and Gynecology, Faculty of Medicine, Saarland University Hospital, 66424 Homburg, Germany
2. Department of Obstetrics and Gynecology, UMF Carol Davila Bucharest, Bucur Maternity, 050474 Bucharest, Romania
3. Department of Medical Microbiology and Hygiene, Faculty of Medicine, Saarland University Hospital, 66424 Homburg, Germany
4. Institute of Medical Biometry, Epidemiology and Medical Informatics, Saarland University Hospital, 66424 Homburg, Germany