Risk factors for cerebral palsy and movement difficulties in 5-year-old children born extremely preterm

Background: Motor impairment is common after extremely preterm (EPT, <28 weeks' gestational age (GA)) birth, with cerebral palsy (CP) affecting about 10% of children and non-CP movement difficulties (MD) up to 50%. This study investigated the sociodemographic, perinatal and neonatal risk factors for CP and non-CP MD.

Methods: Data come from a European population-based cohort of children born EPT in 2011-2012 in 11 countries. We used multinomial logistic regression to assess risk factors for CP and non-CP MD (Movement Assessment Battery for Children - 2nd edition ≤5th percentile) compared to no MD (>15th percentile) among 5-year-old children.

Results: Compared to children without MD (n = 366), young maternal age, male sex and bronchopulmonary dysplasia were similarly associated with CP (n = 100) and non-CP MD (n = 224) with relative risk ratios (RRR) ranging from 2.3 to 3.6. CP was strongly related to severe brain lesions (RRR >10), other neonatal morbidities, congenital anomalies and low Apgar score (RRR: 2.4-3.3), while non-CP MD was associated with primiparity, maternal education, small for GA (RRR: 1.6-2.6) and severe brain lesions, but at a much lower order of magnitude.

Conclusion: CP and non-CP MD have different risk factor profiles, with fewer clinical but more sociodemographic risk factors for non-CP MD.

Impact: Young maternal age, male sex and bronchopulmonary dysplasia similarly increased risks of both cerebral palsy and non-cerebral palsy movement difficulties. Cerebral palsy was strongly related to clinical risk factors including severe brain lesions and other neonatal morbidities, while non-cerebral palsy movement difficulties were more associated with sociodemographic risk factors. These results on the similarities and differences in risk profiles of children with cerebral palsy and non-cerebral palsy movement difficulties raise questions for etiological research and provide a basis for improving the identification of children who may benefit from follow-up and early intervention.