Increasing Prevalence of Cerebral Palsy among Two-Year-Old Children Born at <27 Weeks of Gestation: A Cohort Study

Objective: To evaluate changes in prevalence and severity of cerebral palsy (CP) among surviving children born at <27 weeks of gestation over time and to determine associations between CP and other developmental domains, functional impairment, medical morbidities, and resource use among 2-year-old children who were born extremely preterm. Study design: Retrospective cohort study using prospective registry data, conducted at 25 centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Participants were children born at <27 weeks of gestation and followed at 18 through 26 months of corrected age from 2008 through 2019. Outcomes of interest were changes in prevalence of any CP and severity of CP over time and associations between CP and other neurodevelopmental outcomes, functional impairment, and medical comorbidities. Adjusted logistic, linear, multinomial logistic, and robust Poisson regression evaluated the relationships between child characteristics, CP severity, and outcomes. Results: Among 6927 surviving children with complete follow-up data, 3717 (53.7%) had normal neurologic examinations, 1303 (18.8%) had CP, and the remainder had abnormal neurologic examinations not classified as CP. Adjusted rates of any CP increased each year of the study period (aOR 1.11 per year, 95% CI 1.08-1.14). Cognitive development was significantly associated with severity of CP. Children with CP were more likely to have multiple medical comorbidities, neurosensory problems, and poor growth at follow-up. Conclusions: The rate of CP among surviving children who were born extremely preterm increased from 2008 through 2019. At 18 to 26 months of corrected age, neurodevelopmental and medical comorbidities are strongly associated with all severity levels of CP.