Prevalence and risk factors of low birth weight in a rural district of Bangladesh: a prospective cohort study

BACKGROUND: Low birth weight (LBW, < 2500 gm) is a major contributor to infant morbidity and mortality and is strongly linked to childhood developmental delays. METHODS: To estimate the prevalence of LBW and identify its risk factors, we analyzed data from a community-based prospective cohort study titled, "Aetiology of Neonatal Infections in South Asia". In Bangladesh, the study was conducted in two sub-districts of Sylhet district. The study followed 24,271 pregnant women from 2011 to 2013. The final analysis included 17,643 singleton live-born babies with available birthweight data. To identify risk factors of LBW, we calculated adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) using multivariable modified Poisson regression with robust variance. RESULTS: The prevalence of LBW was 27.61% (95% CI: 26.96-28.28). Maternal factors included undernutrition (MUAC < 22 cm) [aRR 1.19 (95% CI:1.13-1.25)], tobacco use [aRR 1.16 (95% CI: 1.09-1.23)], no antenatal visits with skilled providers [aRR 1.16 (95% CI: 1.07-1.25)], lack of tetanus toxoid vaccination [aRR 1.17 (95% CI:1.11-1.25)], absence of antenatal iron use [aRR 1.10 (95% CI:1.02-1.19)], and pregnancy complications [aRR 1.12 (95% CI:1.05-1.19)]. Other significant factors were lowest household quintile [aRR 1.45 (95% CI: 1.32-1.59)], female sex and residence ≥ 15 km from sub-district hospitals. CONCLUSIONS: The burden of LBW was high in rural Bangladesh. Multiple modifiable maternal factors, including undernutrition, tobacco use, lack of tetanus toxoid vaccination, absence of antenatal iron use and no antenatal care, were associated with increased risk of LBW. Maternal and child health programs should prioritize interventions to address these factors.