1. Department of Obstetrics, Leiden University Medical Center, P.O. Box 9600 (K6-26), 2300 RC Leiden, The Netherlands
2. Department of Obstetrics and Gynecology, IJsselland Ziekenhuis, Capelle a/d IJssel, The Netherlands
3. Department of Clinical Oncology, Leiden University Medical Center, Leiden, The Netherlands
4. Department of Gynecology, Leiden University Medical Center, Leiden, The Netherlands