Chlamydia, Gonorrhea, and Incident HIV Infection During Pregnancy Predict Preterm Birth Despite Treatment.

BACKGROUND: Identifying predictors of preterm birth (PTB) in high-burden regions is important as PTB is the leading cause of global child mortality. METHODS: This analysis was nested in a longitudinal study of human immunodeficiency virus (HIV) incidence in Kenya. HIV-seronegative women enrolled in pregnancy had nucleic acid amplification tests (chlamydia and gonorrhea), rapid plasma reagin (syphilis), wet mount microscopy (Trichomonas and yeast), and Gram stain (bacterial vaginosis); sexually transmitted infection (STI) treatment was provided. PTB predictors were determined using log-binomial regression. RESULTS: Among 1244 mothers of liveborn infants, median gestational age at enrollment was 26 weeks (IQR, 22-31), and at delivery was 39.1 weeks (IQR, 37.1-40.9). PTB occurred in 302 women (24.3%). Chlamydia was associated with a 1.59-fold (P = .006), gonorrhea a 1.62-fold (P = .04), and incident HIV a 2.08-fold (P = .02) increased PTB prevalence. Vaginal discharge and cervical inflammation were associated with PTB, as were age ≤21 (prevalence ratio [PR] = 1.39, P = .001) and any STI (PR = 1.47, P = .001). Associations with chlamydia and incident HIV remained in multivariable models. CONCLUSIONS: STIs and incident HIV in pregnancy predicted PTB despite treatment, suggesting the need for earlier treatment and interventions to decrease genital inflammation.