Background.  Maternal human immunodeficiency virus (HIV) RNA load, CD4 cell count, breast-feeding, antiretroviral use, and malaria are well-established factors associated with mother-to-child transmission (MTCT) of HIV; the role of maternal tuberculosis (TB), however, has not been well established.

Methods.  The study population was 783 HIV-infected Indian mother-infant pair participants in randomized and ancillary HIV-infected cohorts of the Six Week Extended-Dose Nevirapine (SWEN) Study, a study comparing extended nevirapine versus single-dose nevirapine, to reduce MTCT of HIV among breast-fed infants. Using multivariable logistic regression, we assessed the impact of maternal TB occurring during pregnancy and through 12 months after delivery on risk of MTCT.

Results.  Of 783 mothers, 3 had prevalent TB and 30 had incident TB at 12 months after delivery. Of 33 mothers with TB, 10 (30%) transmitted HIV to their infants in comparison with 87 of 750 mothers without TB (12%; odds ratio [OR], 3.31; 95% confidence interval [CI], 1.53–7.29; P = .02). In multivariable analysis, maternal TB was associated with 2.51-fold (95% CI, 1.05–6.02; P = .04) increased odds of HIV transmission adjusting for maternal factors (viral load, CD4 cell count, and antiretroviral therapy) and infant factors (breast-feeding duration, infant nevirapine administration, gestational age, and birth weight) associated with MTCT of HIV.

Conclusions.  Maternal TB is associated with increased MTCT of HIV. Prevention of TB among HIV-infected mothers should be a high priority for communities with significant HIV/TB burden.