1. Department of Obstetrics and Gynaecology , VU University Medical Center , P.O. Box 7057 , 1007 MB Amsterdam , The Netherlands , Tel.: +31 (0) 20 4443239 or +31 (0) 20 4444444, pager 6112, Fax: +31 (0) 20 4443333
2. Neuroscience Campus , VU University , Amsterdam , The Netherlands
3. Department of Child Neurology , VU University Medical Center , P.O. Box 7057, 1007 MB Amsterdam , The Netherlands
4. Department of Pediatric Radiology , VU University Medical Center , P.O. Box 7057, 1007 MB Amsterdam , The Netherlands
5. Department of Obstetrics and Gynaecology , University Medical Center Utrecht , Utrecht , The Netherlands
6. Department of Obstetrics and Gynaecology , VU University Medical Center , P.O. Box 7057, 1007 MB Amsterdam , The Netherlands
7. Research Institute MOVE , VU University , Amsterdam , The Netherlands