1. Department of Obstetrics & Gynecology, Maastricht University Medical Center, Maastricht, the Netherlands
2. Department of Biomedical Engineering, Maastricht University, Maastricht, the Netherlands
3. Department of Epidemiology, Maastricht University, Maastricht, the Netherlands
4. Department of Internal Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
5. Division “Vrouw & Baby”, University Medical Center Utrecht, Utrecht, the Netherlands