[1] Univ Gothenburg, Inst Clin Sci, Dept Pediat, Sahlgrenska Acad, Gothenburg, Sweden
[2] Sahlgrens Univ Hosp, Queen Silvia Childrens Hosp, Reg Rehabil Ctr, Box 210 62, SE-41804 Gothenburg, Sweden
[3] Vestfold Hosp Trust, Cerebral Palsy Register Norway, Tonsberg, Norway
[4] Norwegian Univ Sci & Technol, Fac Med, Dept Lab Med Childrens & Womens Hlth, Trondheim, Norway
[5] Ctr Hosp Univ Lisboa Cent, Area Mulher Crianca & Adolescencia, Cerebral Palsy Registry Portugal, Lisbon, Portugal
[6] Sunderland Royal Hosp, Paediat Dept, Sunderland, England
[7] Publ Hlth England, North England Collaborat Cerebral Palsy Survey, Reg Matern Survey Off, Newcastle Upon Tyne, Tyne & Wear, England
[8] Univ Childrens Hosp, Dept Pediat Neurol, Ljubljana, Slovenia
[9] Toulouse Iii Univ, UMR 1027, Inserm U, Toulouse, France
[10] Univ Hosp, Clin Epidemiol Unit, Toulouse, France
[11] Aarhus Univ Hosp, Child & Adolescent Med, Aarhus, Denmark
[12] Hosp 12 Octubre, Imas12 Ciberesp, Clin Res Unit, Madrid, Spain