Individual, Partner, and Couple Predictors of HIV Infection among Pregnant Women in Malawi: A Case–Control Study

We aimed to understand drivers of HIV-infection in pregnant women in Malawi. The study was conducted in antenatal and labor and delivery wards. HIV-infected women and their partners (cases) were frequency matched in a 1:2 ratio based on age and screening location to HIV-uninfected women and their partners (controls) in a prevalent case–control study. Characteristics associated with female HIV infection were assessed using logistic regression modeling. At screening, HIV-infected women were more likely to have partners outside Lilongwe than HIV-uninfected women (24% vs. 0%, p < 0.0001). Case females were more likely to have HIV-infected study partners than control females (75% vs. 4%, p < 0.0001). The odds of female HIV-infection were higher if either couple member reported ≥ 2 lifetime marriages (OR 9.0, CI 2.6–30.9) or ≥ 3 lifetime partners (OR 18.0, CI 3.1–103.6) and lower if either reported past couple HIV testing and counseling (OR 0.1, CI 0.04–0.3). Targeting women with migrating partners, promoting couple HIV testing and counseling, and limiting partners could slow HIV transmission.