1. CIH LMU Center for International Health, Medical Center of the University of Munich, Leopoldstrasse 7, Munich 80802, Germany
2. Department of Obstetrics and Gynaecology, College of Medicine, University of Nigeria, Nsukka 410108, Nigeria
3. Institute for Medical Information Processing, Biometry and Epidemiology, Ludwig-Maximilians University, Munich, Germany
4. Department of Medicine 4, Grossharden, Ludwig-Maximilians University, Munich 81377, Germany