Decreasing Trends in Birth Prevalence and Severity of Cerebral Palsy in Sweden During 2000–2019: A Population‐Based Registry Study

AIM: To examine temporal trends in cerebral palsy (CP) birth prevalence and changes in functional severity in Sweden between 2000 and 2019. METHODS: This population-based registry study included all children with CP born in Sweden between 2000 and 2019. Annual CP birth prevalence was calculated using Poisson regression. Changes in functional severity were assessed using the Gross Motor Function Classification System (GMFCS) and Manual Ability Classification System (MACS) levels across birth cohorts, with ordinal logistic regression used to examine their association. RESULTS: In total 4281 participants were included. CP birth prevalence decreased over the study period with a rate ratio per year of 0.985 (95% confidence interval 0.980-0.990) corresponding to a 1.5% annual reduction. The proportion of children with milder impairment increased over time. In crude analyses: children born in 2015-2019 had lower odds of higher MACS levels (OR 0.70, 95% CI 0.60-0.83, p ≤ 0.001), and GMFCS level (OR 0.77, 95% CI 0.65-0.92, p = 0.003) than those born in 2000-2004. CONCLUSION: CP birth prevalence in Sweden decreased significantly between 2000 and 2019. A shift toward milder functional impairment was observed in more recent birth cohorts and occurred alongside changes in CP subtype distribution.