Antenatal care utilization and low birth weight in Zambia: Evidence from the Zambia Demographic and Health Survey.

Low birth weight (LBW) poses a formidable threat to child survival and development in sub-Saharan Africa. Although antenatal care (ANC) is the standard clinical channel for delivering maternal and fetal health interventions, the extent to which increased ANC visits lower the likelihood of LBW in Zambia is not fully known. This study evaluated the relationship between ANC attendance frequency and LBW using nationally representative data. A cross-sectional analysis was conducted using data from the Zambia Demographic and Health Surveys (ZDHS). Pooled data from the 2001-2024 survey rounds were used to map spatial and temporal trends in LBW (<2,500 g), while the 2024 dataset was used for the primary regression analysis. The study sample comprised women aged 15-49 years with a most recent singleton live birth and a documented birth weight. Antenatal care attendance was categorized into 0-3, 4-7 and ≥8 visits. Spatial and temporal variation was visualized in R, and survey-weighted proportions, logistic regression models and predicted probabilities were estimated in Stata version 17. A total of 4,178 women were included in the analysis, and the overall weighted prevalence of LBW was 9.0%. Prevalence was highest among women attending 0-3 visits. In adjusted analyses, attending 4-7 visits (AOR 0.57; 95% CI: 0.43-0.77) and ≥8 visits (AOR 0.50; 95% CI: 0.27-0.93) were associated with lower odds of LBW relative to 0-3 visits, and the predicted probability of LBW declined as the number of visits increased. Low birth weight remains a significant public health concern in Zambia. Higher ANC attendance was associated with lower odds of LBW, supporting the importance of adequate and sustained ANC. Strengthening early initiation and continuity of ANC, alongside addressing broader socioeconomic and nutritional determinants, may contribute to improved birth outcomes.