Assessing the impact, barriers and facilitators of peer-driven interventions on the prevention of mother-to-child transmission of HIV in low- and middle-income countries: A systematic review and meta-analysis.

INTRODUCTION

Peer interventions may improve retention across the prevention of mother-to-child transmission (PMTCT) cascade in low- and middle-income countries (LMICs), where poor adherence to antiretroviral therapy (ART) remains a major barrier. This systematic review and meta-analysis evaluated the impact of peer support interventions on PMTCT outcomes to inform scalable strategies.

METHODS

Following PRISMA guidelines, we searched PubMed, Cochrane Library, Scopus and Google Scholar (2008-2025) using terms including 'peer mentors,' 'PMTCT' and 'LMICs.' Independent reviewers conducted data extraction and quality appraisal using Cochrane risk-of-bias tools. Random-effects meta-analysis was performed in R (v4.4.3), with significance set at p < 0.05. Qualitative findings were thematically synthesized.

RESULTS

Twenty-seven studies (n = 26 431) across 10 countries were included. Peer interventions improved ART adherence at one year (OR: 1.19, 95% CI: 1.05-1.35) and two years (OR: 2.04, 95% CI: 1.58-2.64), PMTCT retention at six weeks postpartum (OR: 2.63, 95% CI: 1.56-4.43), infant uptake of HIV prophylaxis (OR: 2.95, 95% CI: 1.90-4.59), early infant diagnosis (OR: 1.64, 95% CI: 1.01-2.67) and viral load testing (OR: 1.21, 95% CI: 1.07-1.38). No significant effects were observed for ART initiation, PMTCT retention at 12 months or HIV status disclosure. Most studies (75%) reported improved exclusive breastfeeding. Barriers included stigma, inadequate mentor training, logistical and economic constraints and poor male involvement; facilitators included training, incentives and community trust.

CONCLUSION

Peer interventions improve adherence, infant prophylaxis and retention but have limited effects on viral suppression and disclosure. Addressing stigma, strengthening health systems and enhancing male engagement may optimize impact.