Introduction Sexually transmitted infections (STI) may increase the risk of perinatal HIV transmission; however, there is limited evidence on risk factors associated with STIs among HIV-infected pregnant women.
Methods We conducted a study of HIV-infected pregnant women (n=199) in antenatal care at 2 primary care facilities in South Africa to evaluate risk factors for STIs. Participants were interviewed and self-collected vulvovaginal swabs which were tested for Chlamydia trachomatis (CT), Neisseria gonorrhoea (NG) and Trichomonas vaginalis (TV), Xpert (Cepheid, Sunnyvale, USA). We report descriptive and multivariate logistic regression results of factors associated with any STI.
Results Median age was 29 years; median gestational age was 20 weeks. Prevalence of any STI was 51%. Of all women 90% reported having sex during pregnancy (of which 9% reported oral sex and 4% anal sex). Most (62%) had sex 7 days prior to study enrolment. Over 70% of women were not virally suppressed (>200 copies/mL) while 99% of women were on antiretroviral therapy. At last sex 75% reported condomless sex and 15% reported having >1 sex partner in the past 12 months. Of women 14% reported any alcohol use during pregnancy of whom 25% reported ≥5 drinks on a typical day. Twenty-two percent reported being in a serodiscordant relationship with father of the child; 27% seroconcordant relationship; 51% didn’t know. Odds of having any STI decreased as age increased (OR/year=0.93; 95%CI=0.88–0.98). Odds increased with increased gestational age at time of testing (aOR=1.07;95%CI=1.02–1.12) and recent sex (past 30 days vs. longer) (aOR=1.42;95%CI=1.04–1.93). Trends toward increased odds of any STI included:>1 partner (aOR=2.36;95%CI=0.96–5.84;p=0.06) and ≥ 5 drinks daily (aOR=3.61;95%CI=0.77–35.7;p=0.09), adjusted for age.
Conclusion Nearly all HIV-infected pregnant women were sexually active during pregnancy with behaviours associated with increased risk for STIs: condomless sex, anal sex, alcohol use or multiple partners. Interventions to reduce STI risk during pregnancy are urgently needed.