Antenatal Screening for Sexually Transmitted Infections to Reduce Preterm Birth or Low Birthweight (Philani Ndiphile Study): A Randomized 3-Group Trial

Abstract

Abstract Background Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis are predominantly asymptomatic curable sexually transmitted infections (STIs) associated with adverse birth outcomes. Whether antenatal STI screening improves birth outcomes remains uncertain. Methods In this randomized trial (NCT04446611), pregnant women ≥18 years were assigned before 27 weeks' gestation to (1) screening and treatment for C. trachomatis, N. gonorrhoeae, and T. vaginalis at enrollment, with tests-of-cure (1-Time Screening); (2) screening and treatment at enrollment, repeated at 30–34 weeks (2-Time Screening); or (3) Standard-of-Care (syndromic management). The primary outcome was a composite of preterm birth (<37 weeks' gestation) or low birthweight (<2500 g); each component was evaluated individually as a secondary outcome. Results Of 2247 enrolled, 1910 had live births. The composite outcome occurred in 22.9% of the 1-Time Screening (RR 0.99; 95% CI .81–1.21) and 20.6% of the 2-Time Screening groups (RR 0.89; 95% CI .72–1.09), compared with 23.2% of the Standard-of-Care group. Preterm birth occurred in 18.9% of the 1-Time Screening group (RR 1.00; 95% CI .80–1.26), 14.5% of the 2-Time Screening group (RR 0.77; 95% CI .60–0.99), and 18.8% of the Standard-of-Care group. Low birthweight occurred in 14.1% of the 1-Time Screening group (RR 1.10; 95% CI .83–1.46), 12.9% of the 2-Time Screening group (RR 1.01; 95% CI .76–1.35), and 12.8% of the Standard-of-Care group. Conclusions Neither STI screening strategy reduced the primary composite outcome or low birthweight alone. The 2-Time Screening strategy reduced preterm birth by 23%.

The authors' abstract, as published at the source. Clinical Infectious Diseases, 2026 · DOI ↗