Malnutrition in infants aged under 6 months: prevalence and anthropometric assessment – analysis of 56 low- and middle-income country DHS datasets

Introduction

Tackling malnutrition in infants aged under 6 months (u6m) is a major global priority yet evidence around this vulnerable group is weak. We aimed to support the rollout of new 2023 WHO guidelines by examining the burden of infant malnutrition and potential programme caseloads with new enrolment criteria.

Methods

Secondary analysis of Demographic and Health Survey (DHS) datasets. We calculated the number of underweight (low weight-for-age), wasting (low weight-for-length), stunting (low length-for-age) and low birth weight (LBW) infants. We assessed data quality by recording extreme or missing values. We calculated the population-weighted prevalence of anthropometric deficit and extrapolated to all low- and middle-income countries (LMICs). We regressed being underweight and wasti on infant, maternal and household characteristics using logistic regression.

Results

We analysed 56 DHS surveys. There were more extreme (flagged) values for length-based measures (7.5% flagged for weight-for-length, 3.8% for length-for-age) than for weight-for-age (0.6% flagged). Overall, 17.4% of infants (95% CI: 16.9 to 18.0) were underweight, 15.5% (15.0–16.0) were wasted, 19.9% (19.3–20.5) were stunted and 15.0% (14.5–15.5) were LBW. This corresponds to an estimated burden in LMICs of 10.3 million underweight infants (4.1 million severely underweight), 9.2 million wasted (4.0 million severely wasted), 11.8 million stunted (5.4 million severely stunted) and 8.9 million LBW infants. Overlap of the indicators varied markedly in different regions/countries. Numerous factors were associated with both underweight and wasting; associations tended to be stronger and have greater biological plausibility with being underweight.

Conclusion

Malnutrition in infants u6m is a major problem in LMICs. Local epidemiology should inform case identification in contextualised care services across health and nutrition. Data quality and stronger associations with health and social characteristics support the use of underweight as a key enrolment criterion. Since vulnerability may be due to or exacerbated by multiple factors, management must go beyond feeding support to address wider infant, maternal and mental health and social circumstances through integrated, multidisciplinary care systems.