Neurological and neurodevelopmental outcomes in neonates and children after maternal chikungunya infection in pregnancy: a systematic review and meta-analysis.

Background: Chikungunya virus (CHIKV) is a re-emerging Aedes-borne virus with documented vertical transmission in pregnancy. Neurological and neurodevelopmental outcomes in neonates and children have important clinical and societal implications, yet evidence remains limited and fragmented. We therefore undertook a quantitative meta-analysis and narrative synthesis on neurological and neurodevelopmental outcomes in neonates and children after maternal chikungunya infection in pregnancy. Methods: In this systematic review and meta-analysis, we searched PubMed, Embase, Web of Science, and Scopus from inception to January 3, 2026, with no language restrictions. We included observational studies reporting neurological outcomes in neonates and/or children after maternal CHIKV infection during pregnancy. Prespecified exclusion criteria were duplicate records/publications; non-original reports; non-human studies; and reports without useable outcome data for synthesis. Quantitative outcomes were: (1) the pooled proportion of acute neonatal neurological outcomes among neonates with confirmed vertical CHIKV infection (≤28 days), and (2) the relative risk (RR) of adverse neurodevelopmental outcomes (>28 days) in children born to mothers with CHIKV infection compared with children of uninfected mothers. Quantitative outcomes were pooled using random-effects meta-analysis (Freeman-Tukey for proportions; inverse-variance pooling for RRs), with heterogeneity assessed by I Findings: The search identified 1080 records; 26 studies met inclusion criteria. All 26 contributed to the qualitative synthesis and 9 entered the quantitative meta-analysis. Among neonates with confirmed vertical CHIKV infection, the pooled proportion with neurological outcomes was 48.0% (95% CI 24.0-73.0; 7 studies; n = 157 neonates; I Interpretation: Our findings suggest that vertical CHIKV infection often causes early neonatal neurological manifestations, and maternal infection in late pregnancy or the perinatal period may be associated with a nearly twofold increase in adverse long-term neurodevelopment in offspring. However, these inferences are based on a small, predominantly observational evidence base with heterogeneous outcome definitions and ascertainment, which limits the precision and comparability of pooled estimates. Despite a limited and heterogeneous evidence base, these findings support proactive identification of high-risk peripartum exposure, targeted diagnostic testing and close observation during the first postnatal week, and longitudinal developmental follow-up. From a public-health perspective, they emphasize the importance of mosquito-bite prevention for pregnant women and robust vector control, as well as strengthened newborn monitoring and timely access to early-intervention and family support services in affected settings. Funding: Prevention and Control of Emerging and Major Infectious Diseases-National Science and Technology Major Project; National Natural Science Foundation of China.