Improving perinatal outcomes among pregnant women affected by HIV with an integrated STI testing model: study protocol for a randomized controlled trial (PrIMI Study)

Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV) infections in pregnancy are associated with fetal loss, preterm birth, small-for-gestational age, infant mortality, and other adverse outcomes. Approximately one in four pregnant women in East Africa have at least one of these sexually transmitted infections (STIs). Syndromic STI management persists as standard of care leading to untreated asymptomatic infections and inappropriate antibiotic treatment for symptomatic women without an STI. The World Health Organization calls for antenatal STI testing models in high-burden priority settings with robust cost-benefit data. We designed a randomized trial in Kisumu and Siaya to compare models of STI testing in antenatal care. The Preventing Infections in Mothers and Infants (PrIMI) study is an unblinded 3-arm individual-level randomized controlled trial in Kisumu and Siaya, Kenya to compare perinatal outcomes associated with 3 models of STI testing and management in antenatal care. Overall, 3132 eligible pregnant women seeking antenatal care will be enrolled and randomized 1:1:1 to receive standard of care (syndromic management only without etiological CT, NG, or TV testing) vs. etiological CT, NG, and TV testing universally vs. only among women without STI symptoms. Women with STIs detected and/or symptoms per the Kenyan Ministry of Health algorithms will receive immediate treatment, expedited partner treatment per national guidelines, and tests of cure. Participants will be followed through 9 months postpartum. We will quantify and compare a composite outcome of pregnancy loss, stillbirth, preterm birth, low birthweight, small-for-gestational age, and neonatal death between randomization arms. Additionally, several secondary (STI prevalence, quality of care, expedited partner treatment outcomes) and exploratory outcomes (HIV incidence, individual perinatal outcomes, NG antimicrobial resistance) will be explored. We hypothesize that universal CT, NG, and TV testing versus standard of care syndromic STI management alone will improve perinatal outcomes among pregnant women seeking antenatal services at routine clinics. Our results will guide policymakers to integrating STI testing into maternal health systems. The study was initiated on January 27, 2025, and is expected to be completed by March 2027. ClinicalTrials.gov NCT06203951, https://clinicaltrials.gov/ct2/show/NCT06203951 . Registered on 14 September 2024.