High prevalence of sexually transmitted infections among pregnant women in southern Ethiopia: evidence from routine laboratory diagnosis

Background: Sexually transmitted infections (STIs) remain a major public health concern among pregnant women in low-resource settings such as Ethiopia. Today, their true prevalence is underestimated due to syndromic management, which misses asymptomatic infections. Indeed, limited resources restrict a test and treat approach, and routine antenatal care (ANC) screening is usually confined to HIV and syphilis. This study assessed the prevalence of common STIs using routinely available diagnostic methods to generate baseline evidence for application in ANC. Methods: A cross-sectional study was conducted from July to December 2024 among 743 pregnant women at ≤16 weeks gestation. Vaginal swabs were examined for Trichomonas vaginalis using wet mount and Neisseria gonorrhoeae using Gram stain. HIV and syphilis screening were performed using SD BIOLINE Duo kit. Data were collected with REDCap, and complex-sample logistic regression analyzed factors associated with STIs. Result: Of 743 women, 91 (12.2%; 95% CI: 10.1–14.8) had at least one STI, of which 62.6% (57/91) were asymptomatic. Factors associated with STIs included being a merchant (AOR = 1.80; 95% CI: 1.05–3.11), lack of media usage (AOR = 0.60; 95% CI: 0.39–0.91), low wealth index (AOR = 1.51; 95% CI: 1.08–2.10), and presence of clue cells (AOR = 3.47; 95% CI: 1.29–9.35). Conclusion: STIs remain prevalent and frequently asymptomatic, highlighting the inadequacy of syndromic management in ANC. Social, economic and biological factors predict infection, emphasizing the need for routine laboratory-based screening and targeted interventions. Future research should use molecular diagnostics to capture comprehensive STIs prevalence.