Cord Blood Treatment for Children With Cerebral Palsy: Individual Participant Data Meta-Analysis.

Context: Umbilical cord blood (UCB) is a novel treatment for cerebral palsy (CP), with trials indicating UCB can improve gross motor function. However, heterogeneity has limited the ability to interpret findings.

Objective: Assess the safety and efficacy of UCB for improving gross motor function in children with CP, including exploring cell dose effect and responder subgroups.

Data Sources: Individual participant data from published reports and registered trials identified via systematic searches.

Study Selection: Studies administering UCB to individuals with CP collecting Gross Motor Function Measure (GMFM) scores.

Data Extraction: A 1-stage individual participant data meta-analysis was conducted in R to obtain the pooled effect of UCB and cell dose effect on GMFM using linear mixed models. Responder subgroups were also investigated.

Results: Four hundred ninety-eight participant data records were obtained from 11 studies. Main analysis of 170 participants treated with UCB and 171 controls demonstrated UCB increased mean GMFM-66 score compared with controls by 1.36 points at 6 months (95% CI, 0.41-2.32; P = .005) and 1.42 at 12 months (95% CI, 0.31-2.52; P = .012). Mean GMFM-66 effect size increased with increasing cell dose at 3 (P < .001) and 12 months (P = .047). CP severity and baseline age were associated with GMFM-66 effect size. The rate of serious adverse events was similar between groups.

Limitations: Heterogeneity across variables and time points, reducing subanalysis power.

Conclusions: UCB is safe and provides benefit for improving gross motor function in some children with CP, with higher doses associated with increased effect size. Younger participants (aged approximately <5 years) with milder CP showed increased benefit. Findings will help design future trials with precision.