Age-related disparities and spatial distribution of low birthweight in sub-Saharan Africa: using data from demographic and health survey

In Sub-Saharan Africa (SSA), the burden of low birthweight (LBW) remains high, leading to considerable short- and long-term consequences for both newborns and mothers. However, limited evidence exists on the disparities and geographical distribution of LBW among adolescent (15-19 years) and non-adolescent women (20-49 years). This study aimed to assess the age-related disparity, geospatial distribution and determinants of LBW in SSA. The study used Demographic and Health Survey (DHS) data from 33 SSA countries released between 2010 and 2023. Concentration curves and indices, absolute and relative difference measures, spatial autocorrelation and hotspot analysis, and multilevel modelling were employed to explore differences in LBW by maternal age group. A total of 27,889 (15.5%) of adolescent women and 152,521 (84.5%) non-adolescent women were included in the analysis. LBW was significantly concentrated among adolescents (CI = - 0.096, p < 0.001), with a 13.2% prevalence compared to 8.3% in non-adolescents, highlighting a 4.9% absolute difference (relative difference = 1.60, p < 0.001). Lower educational level, unemployment, fewer number of antenatal care (ANC) visits, lacking permission to get medical care and being single marital status were the common variables significantly associated with LBW in both adolescent and non-adolescent women. However, unintended pregnancy and early sexual initiation were significantly associated with LBW in only adolescent women while distance to healthcare facilities and lower parity were found to be significantly associated with LBW only in non-adolescent women. At community level, region was a significant factor for LBW in both groups. Spatial autocorrelation and hotspot analysis showed that LBW was randomly distributed among adolescents (Moran's test of - 0.0106 and p value = 0.904) but clustered in Mauritania, Mali, Niger, and Chad for non-adolescent women. This study found significant age-related disparities in LBW across SSA, with adolescent mothers facing a disproportionate burden. This underscores the need to focus on preventing adolescent pregnancy and providing support for pregnant adolescents by improving access to ANC, education, and economic empowerment to prevent adverse birth outcomes. Random distribution of LBW in adolescent women indicates the need for adolescent-specific regional interventions across SSA countries.