1. Department Obstetrics & Gynaecology; Ziekenhuis Oost Limburg; Genk Belgium
2. Department of Medicine and Life Sciences; Hasselt University; Hasselt Belgium
3. I-BioStat; Hasselt University; Hasselt Belgium
4. I-BioStat; University of Leuven; Leuven Belgium
5. Department of Physiology; Hasselt University; Hasselt Belgium