Assessing regional disparities and sociodemographic influences on short birth intervals (SBI) among reproductive-age women in Nigeria

Short birth interval (SBI), defined as < 33 months between two consecutive live births, remains a pressing public health concern in Nigeria, with potential adverse consequences for both mothers and children. Understanding the factors associated with SBI is crucial for developing effective interventions to improve maternal and child health outcomes. This study investigates the sociodemographic and regional disparities influencing SBI among women of reproductive age in Nigeria, utilizing data from the 2018 Nigeria Demographic and Health Survey (NDHS). This study analysed data from 25,280 women of reproductive age who had given birth within five years preceding the NDHS survey. Bivariate and multivariable logistic regression analyses were conducted to assess the relationship between SBI and associated factors. Prevalence rates were analysed and presented using map and chart to highlight regional disparities. The overall prevalence of SBI in Nigeria was 51.6%. Older age was associated with a higher likelihood of optimal birth interval (AOR = 3.23, 95% confidence interval [CI]: 2.32-4.50, p < 0.001). Women in the South East (55.3%) and North West (52.2%) regions had the highest prevalence of SBI, while the South West had the lowest (38.4%). South East had lower odds of optimal BI (AOR = 0.67, 95% CI: 0.59-0.75, p < 0.001) compared to the North Central region. Higher education (AOR = 0.85, 95% CI: 0.74-0.99, p = 0.03) was associated with reduced odds of SBI, but wealth index did not show significant associations in the adjusted analysis. This study highlights significant regional disparities in short birth interval SBI in Nigeria. Interventions addressing regional and educational disparities, particularly in underserved regions, are essential for promoting optimal birth intervals and improving maternal and child health outcomes.