1. Department of Obstetrics and Prenatal Medicine, Asklepios Clinic Hamburg‐Barmbek, Asklepios Medical School University of Semmelweis Hamburg Germany
2. German Task Force for Obstetrics and Prenatal Medicine, AGG ‐ Section Preterm Birth Hamburg Germany
3. Department of Obstetrics and Gynecology, Marienhaus Klinikum Neuwied Neuwied Germany