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

SUMMARY Background Chlamydia trachomatis , Neisseria gonorrhoeae , and Trichomonas vaginalis are curable sexually transmitted infections (STIs) associated with adverse birth outcomes. Most infections are asymptomatic. Whether antenatal STI screening improves birth outcomes remains uncertain. Methods In a randomized three-group trial in South Africa, pregnant women aged 18 years or older were assigned before 27 weeks’ gestation to: (1) screening and treatment for Chlamydia trachomatis, Neisseria gonorrhoeae , and Trichomonas vaginalis at enrollment, with tests-of-cure (One-Time Screening); (2) screening and treatment at enrollment, repeated at 30 to 34 weeks (Two-Time Screening); or (3) Standard-of-Care (Syndromic management). The primary outcome was a composite of preterm birth (