1. Department of Laboratory Medicine, Children's and Women's Health; Faculty of Medicine; Norwegian University of Science and Technology; Trondheim Norway
2. The Cerebral Palsy Register of Norway; Habilitation Centre; Vestfold Hospital Trust; Tønsberg Norway
3. Department of Obstetrics and Gynecology; Akershus University Hospital; Lørenskog Norway
4. Institute of Clinical Medicine; University of Oslo; Oslo Norway