Magnitude of short birth intervals and associated factors among reproductive-age women in sub-Saharan Africa: a multilevel modified Poisson regression analysis of recent DHS data (2021-2024).

backgroundShort birth intervals remain a significant public health concern in sub-Saharan Africa (SSA), adversely affecting maternal and child health. Although socioeconomic, reproductive and healthcare factors influence birth spacing, evidence from recent demography and health survey (DHS) data is limited. This study aims to determine the magnitude of short birth intervals and identify associated factors among reproductive-age women in SSA using multilevel modified Poisson regression, providing easily interpretable evidence to inform policy and intervention programs.

methodsThis cross-sectional study analyzed recent DHS data from SSA countries to examine short birth intervals and associated factors among women aged 15–49 years. A total weighted sample of 345,958 women was included. Multilevel mixed-effects modified Poisson regression was used to account for clustering and estimate adjusted prevalence ratios (APR), with the significance level set at p < 0.05.

resultsThe median birth interval was 32 months. The prevalence of short birth intervals among reproductive-age women in SSA was 50.4% (95% CI: 50.2–50.6). Women aged 25–34 years (APR = 0.76, 95% CI: 0.74–0.77) and 35–49 years (APR = 0.65, 95% CI: 0.63–0.66), literate women (APR = 0.93, 95% CI: 0.91–0.94), women with media exposure (APR = 0.97, 95% CI: 0.95–0.98), those from middle-wealth (APR = 0.97, 95% CI: 0.96–0.98) and rich households (APR = 0.90, 95% CI: 0.88–0.92), women with one under-five child (APR = 0.88, 95% CI: 0.86–0.90), women with a history of abortion (APR = 0.97, 95% CI: 0.96–0.98), current family planning users (APR = 0.98, 95% CI: 0.97–0.99), currently breastfeeding women (APR = 0.89, 95% CI: 0.88–0.90), and women with health insurance (APR = 0.90, 95% CI: 0.89–0.93) had a lower prevalence of short birth intervals. Conversely, a higher prevalence of short birth intervals was observed among rural residents (APR = 1.06, 95% CI: 1.04–1.09), women with primary (APR = 1.03, 95% CI: 1.02–1.05) or secondary and higher education (APR = 1.04, 95% CI: 1.02–1.07), women whose husbands had primary (APR = 1.02, 95% CI: 1.01–1.04) or secondary and higher education (APR = 1.04, 95% CI: 1.02–1.06), women living in households with ≥ 5 members (APR = 1.09, 95% CI: 1.07–1.12), those with ≥ 5 living children (APR = 1.36, 95% CI: 1.34–1.40), those with ≥ 3 under-five children (APR = 1.10, 95% CI: 1.08–1.12), women whose husbands alone (APR = 1.03, 95% CI: 1.02–1.05) or jointly with them (APR = 1.02, 95% CI: 1.01–1.03) made family planning decisions, and women who reported distance to a health facility as a big problem (APR = 1.03, 95% CI: 1.02–1.04).

conclusionShort birth intervals remain highly prevalent among reproductive-age women in SSA. Socioeconomic status, reproductive history, family planning use, and access to health services significantly influence birth intervals. Strengthening women’s empowerment, improving access to family planning and maternal health services, and addressing rural and household-level disadvantages are essential to promote optimal birth spacing and improve maternal and child health outcomes. CLINICAL TRIAL NUMBER: Not applicable.