Cerebral palsy in Norwegian children according to birth characteristics

The aim of this study was to examine trends in the prevalence of cerebral palsy according to birth characteristics among Norwegian children born between 2002 and 2018, as well as associations between birth characteristics, subtypes of cerebral palsy and gross motor function.

Data from the Norwegian Quality and Surveillance Registry for Cerebral Palsy were linked with the Medical Birth Registry of Norway. The prevalence of cerebral palsy per 1000 live births was calculated for the categories gestational age at birth, birth weight and small for gestational age. Trends were analysed using logistic regression, and distributions by subtype and level of gross motor function were analysed using descriptive statistics.

Among 1,006,537 live-born children, 1897 were diagnosed with cerebral palsy. Most children with cerebral palsy were born at term with a normal birthweight. The prevalence of cerebral palsy was higher among children born preterm, with a low birth weight or small for gestational age. The prevalence among term-born children decreased from 1.30 per 1000 live births in 2002 to 0.90 in 2018 (-3.4 % per year, odds ratio (OR) 0.966; 95 % confidence interval (CI) 0.954 to 0.978), while the prevalence among preterm children remained stable. Most children had spastic hemiplegia or diplegia and mild gross motor impairment across birth characteristics.

The prevalence of cerebral palsy in children born at term has decreased, but they still constitute the majority. Across birth characteristics, children predominantly had less severe subtypes and mild gross motor impairments.