Abstract Introduction Childhood stunting remains a major public health challenge in low- and middle-income countries (LMICs). Inadequate water, sanitation, and hygiene (WASH) conditions contribute to recurrent infections and chronic undernutrition; however, evidence regarding which specific WASH components most strongly influence stunting remains inconsistent. This study aimed to systematically evaluate the association between WASH practices and childhood stunting in LMICs. Methods We conducted a systematic review and meta-analysis following PRISMA 2020 guidelines. PubMed, Scopus, Web of Science, Cochrane Library, Epistemonikos, EBSCOhost, and Google Scholar were searched up to July 2025. Observational studies from LMICs assessing associations between WASH practices and childhood stunting were included. Study quality was evaluated using the Newcastle–Ottawa Scale. Random-effects meta-analyses were used to pool odds ratios (ORs) with 95% confidence intervals, with publication bias and sensitivity analyses performed. Results Sixteen studies involving 36,574 children were included. Improved water quality (OR = 0.39; 95% CI: 0.18–0.87) and water accessibility (OR = 0.69; 95% CI: 0.49–0.98) were significantly associated with lower odds of stunting, whereas drinking water source and household water treatment were not. Among sanitation indicators, improved sanitation facility type (OR = 0.71; 95% CI: 0.53–0.94) and environmental sanitation (OR = 0.05; 95% CI: 0.00–0.64) were significantly associated with lower odds of stunting, while toilet access, safe disposal of child feces, and garbage disposal showed no consistent associations. Hygiene practices were also associated with lower odds of stunting, particularly hand hygiene (OR = 0.54; 95% CI: 0.30–0.98) and family hygiene (OR = 0.40; 95% CI: 0.21–0.74), whereas general hygiene was not significantly associated with stunting. Substantial heterogeneity was observed across several outcomes. Conclusions Several WASH components were associated with lower odds of childhood stunting in LMICs, with more consistent evidence for drinking water quality, water accessibility, and sanitation facility type. Findings for other components were inconsistent. Given substantial heterogeneity and the observational nature of included studies, these results should be interpreted cautiously, and further research is needed to establish causal relationships. Trial registration PROSPERO CRD420251145998.
Wijayanto et al. (Tue,) studied this question.