Abstract
BACKGROUND: Exclusive breastfeeding (EBF) is a critical intervention for reducing childhood morbidity and mortality, yet global EBF rates remain below targets. In Tanzania, EBF rates vary widely across regions, with reported disparities influenced by individual, familial, and health system factors. Despite increasing national prevalence rates of EBF from 41% in 2005 to 64% in 2022, localized studies show lower prevalence ranging from 20 to 30%, highlighting the need for a comprehensive synthesis of evidence on the determinants of EBF to inform policy in Tanzania. METHODS: We searched PubMed, Scopus, and CINAHL for peer-reviewed studies from 2014 to 2024 assessing EBF determinants among Tanzanian infants aged less than 6 months. Data was critically appraised using Joanna Briggs Institute tools, and synthesized via random-effects meta-analysis to pool the Odds Ratios of determinants of EBF. The review is registered with PROSPERO: CRD42024566722 RESULTS: A total of 183 studies were identified and 130 underwent title and abstract screening. Fourteen were retrieved for full text screening and 11 met inclusion criteria and were included for analysis. Four studies were among HIV positive mothers and six studies were from Northern Tanzania. Meta analysis of 14 determinants revealed that married/cohabiting mothers had significantly higher odds of EBF (OR 1.63, 95% CI: 1.12,2.36) compared to single mothers. Sub-group analysis among HIV positive mothers showed that employed mothers had higher odds of EBF (OR 1.37, 95% CI: 1.10,1.72). CONCLUSION: Marital status is a key determinant of EBF in Tanzania, underscoring the role of interpersonal and household support. To accelerate progress toward the 70% EBF target, targeted lactation support should be given to the vulnerable groups including single mothers. At national level, interventions should address regional disparities, engage families and communities in breastfeeding education and strengthen infant feeding counselling for HIV positive mothers. Future research should expand coverage to understudied regions and employ qualitative approaches and longitudinal designs to strengthen the evidence base. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13006-025-00790-w.