Effects of short birth interval on child malnutrition in the Asia-Pacific region: Evidence from a systematic review and meta-analysis

Child malnutrition remains a significant concern in the Asia-Pacific region, with short birth intervals recognised as a potential risk factor. However, evidence of this association is inconclusive. This study aimed to systematically review the existing evidence and assess the summary effects of short birth interval on child malnutrition in the Asia-Pacific region. Five electronic databases were searched in May 2023 to identify relevant studies reporting the association between short birth interval and child malnutrition, including stunting, wasting, underweight, anaemia and overall malnutrition, in Asia-Pacific region between September 2000 and May 2023. Fixed-effects or random-effects meta-analysis was performed to estimate the summary effects of short birth interval on child malnutrition. Out of 56 studies meeting the inclusion criteria, 48 were included in quantitative synthesis through meta-analysis. We found a slightly higher likelihood of stunting (n = 25, odds ratio [OR] = 1.13; 95% confidence interval [CI]: 0.97-1.32) and overall malnutrition (n = 3, OR = 2.42; 95% CI: 0.88-6.65) among children born in short birth intervals compared to those with nonshort intervals, although the effect was not statistically significant. However, caution is warranted due to identified heterogeneity across studies. Subgroup analysis demonstrated significant effects of short birth intervals on child malnutrition in national-level studies and studies with larger sample sizes. These findings underscore short birth intervals as a significant contributor to child malnutrition in the Asia-Pacific region. Implementing effective policies and programs is vital to alleviate this burden, ultimately reducing child malnutrition and associated adverse outcomes, including child mortality.