Epidemiologic associations with cerebral palsy

ObjectiveTo estimate epidemiologic risk factors for cerebral palsy.MethodsData were collected by linkage to state-based perinatal repositories and cerebral palsy registers and using a maternal questionnaire. The cohort included 587 individuals with cerebral palsy and 1,154 non-cerebral palsy controls.ResultsThe following factors were associated with cerebral palsy: recorded maternal infection during pregnancy (41.4% patients compared with 31.3% controls; odds ratio [OR] 1.55, 95% confidence interval 1.26-1.91), small for gestational age ([birth weight less than third customized centile] 43.9% patients compared with 6.3% controls; OR 11.75, 6.25-22.08), gestational age less than 32 weeks (29.3% patients compared with 0.7% controls; OR 59.20, 28.87-121.38), multiple birth (OR 6.62, 4.00-10.95), a relative with cerebral palsy (OR 1.61, 1.12-2.32), breech position (13.7% patients compared with 6.0% controls; OR 2.48, 1.76-3.49), bleeding at any time in pregnancy (29.3% patients compared with 16.9% controls; OR 2.04, 1.61-2.58), male sex (58.8% patients compared with 45.8% controls; OR 1.68, 1.38-2.06), multiple miscarriage (7.7% patients compared with 3.5% controls; OR 2.30, 1.38-3.82), smoking (14.0% patients compared with 10.6% controls; OR 1.37, 1.02-1.85), and illicit drug use (3.3% patients compared with 1.5% controls; OR 2.22, 1.14-4.30). Factors not associated with cerebral palsy were "disappearing twin," diabetes, maternal body mass index, hypertension, alcohol consumption, anemia, maternal hypothyroidism, forceps or vacuum delivery, and maternal age.ConclusionPreterm birth, intrauterine growth restriction, perinatal infection, and multiple birth present the largest risks for a cerebral palsy outcome. Reassuringly, upper respiratory tract and gastrointestinal infections during pregnancy were not associated with cerebral palsy.Level of evidenceII.Michael E. O'Callaghan, Alastair H. MacLennan, Catherine S. Gibson, Gai L. McMichael, Eric A. Haan, Jessica L. Broadbent, Paul N. Goldwater, and Gustaaf A. Dekker for the Australian Collaborative Cerebral Palsy Research Grou