Growth patterns in children and adolescents with cerebral palsy from Argentina and Germany

**Background:** Children with cerebral palsy (CP) exhibit delayed growth compared to typically developing (TD) peers, with greater deficits in those with severe motor impairment. Growth patterns in TD children vary between countries due to environmental and ethnic factors, but whether similar cross-country differences exist in children with CP has not been previously studied. This study aimed to compare growth patterns between Argentinian and German children with CP, examine differences by age, motor severity, and feeding modality, and assess the fit of WHO and US CP growth reference charts.

**Methods:** This was a cross-sectional, retrospective study including 799 children with confirmed CP (399 from Argentina, 400 from Germany) aged 2 to 19 years (mean age 9 years 5 months, SD 4 years 7 months). Argentinian data were collected from five cities between 2016–2018; German data were from medical records at the University Children's Hospital, Munich (2012–2019). Children with genetic/metabolic syndromes (n=40) or incomplete data (n=71) were excluded. Anthropometric measurements (weight, height) were converted into z-scores using WHO international growth references, national growth charts (SAP for Argentina, KiGGS for Germany), and US CP growth charts. Bivariate analysis (t-tests) and Generalized Linear Models (GLM) with interaction effects were used to analyze associations between z-scores and covariates (country, sex, GMFCS level, feeding modality, age). Statistical significance was set at p<0.01.

**Key Results:** Compared to WHO references, Argentinian children with CP had lower z-scores than German children across all GMFCS levels. For height-for-age (HAZ), the decrease with age in Argentina (−0.144 z-score/year) was double that in Germany (−0.073 z-score/year). Children with GMFCS IV–V showed a significant decline in BMIZ with age (−0.102 z-score/year, p<0.001). Using US CP charts, both countries showed decreasing HAZ with age (Argentina: −0.066/year; Germany: −0.032/year; both p<0.001). BMIZ increased more among children with feeding tubes (0.062 z-score/year) compared to oral feeding (0.042 z-score/year; both p<0.001). For weight-for-age (WAZ) using US CP charts, Argentinian children with oral feeding had significantly lower z-scores (−0.553, p<0.001) compared to those with non-oral feeding. WHO charts showed excellent fit for BMIZ in GMFCS I–III but poor fit for HAZ overall. US CP charts showed good fit for BMIZ and WAZ but overestimated height (HAZ >0 for all subgroups).

**Clinical Implications:** This study demonstrates for the first time that ethnic and environmental growth differences observed in TD children also manifest in children with CP. German children with CP were taller than Argentinian children, mirroring population-level height differences between Northern European and South American populations. The findings highlight the importance of considering country-specific growth patterns when monitoring children with CP. The greater height deficit in Argentinian children—especially those with severe motor impairment—may reflect disparities in healthcare access, nutrition, and socioeconomic conditions. The authors recommend earlier detection of CP in Argentina, improved access to specialized nutritional assessment, and economic support for affected families. US CP growth charts are useful for BMI monitoring but may underestimate height deficits, particularly in non-US populations. Limitations include potential selection bias (more severe cases in the Argentinian sample), retrospective data collection, and lack of pubertal status assessment. Future research should examine how environmental factors and healthcare systems affect growth outcomes in children with CP across different countries.