1. Department of Obstetrics and Gynecology, University Hospital Brugmann, Université Libre de Bruxelles, Brussels, Belgium
2. Department of Obstetrics and Gynecology, University Hospital St Pierre, Université Libre de Bruxelles, Brussels, Belgium
3. Labocita, Citadelle Hospital, Liège, Belgium
4. Department of Blood Transfusion, University Hospital Brugmann, Brussels, Belgium
5. Ars Statistica, Nivelles, Belgium