Abstract
<jats:title>ABSTRACT</jats:title> <jats:sec> <jats:title>Background</jats:title> <jats:p> Curable sexually transmitted infections (STIs) are associated with adverse birth outcomes, yet little cost-effectiveness evidence guides antenatal STI screening policy in high-burden settings. We conducted a cost-effectiveness and cost-utility analysis of the Philani Ndiphile trial in South Africa, comparing One-Time and Two-Time antenatal screening for <jats:italic>C. trachomatis, N. gonorrhoeae,</jats:italic> and <jats:italic>T. vaginalis</jats:italic> with standard syndromic management. </jats:p> </jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>A decision-analytic model from the provider perspective simulated costs and outcomes for pregnant women and infants. Costs included diagnostics, treatment, and neonatal hospitalisation for a primary composite outcome of preterm birth and/or low birthweight and its components (secondary trial outcomes). Modelled outcomes included incremental cost (US$) per composite (preterm birth and/or low birthweight) case, per component case and per disability-adjusted life year (DALY) averted. The analysis captured infant outcomes in the first year. Univariate and probabilistic sensitivity analyses were conducted to assess parameter uncertainty and robustness of results.</jats:p> </jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p> Screening for <jats:italic>C. trachomatis, N. gonorrhoeae,</jats:italic> and <jats:italic>T. vaginalis</jats:italic> twice during pregnancy was not cost-effective for preventing the primary composite outcome, nor for preventing low birthweight alone. However, two-time screening was cost-saving for preventing preterm birth alone, averting more DALYs and thereby yielding better health outcomes while reducing healthcare costs compared with syndromic management. One-time screening was not cost-effective for preventing any outcome. </jats:p> </jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p> Repeat antenatal screening for <jats:italic>C. trachomatis, N. gonorrhoeae</jats:italic> , <jats:italic>and T. vaginalis</jats:italic> has the potential to prevent preterm births while reducing healthcare costs in high-burden settings. These findings support further research to confirm the clinical effectiveness of repeat screening and to evaluate longer-term health and economic impacts. </jats:p> </jats:sec>