BACKGROUND: Pregnancy increases METHODS: We measured adaptive immune responses from 33 participants (HIV+ 21, HIV- 12) with positive interferon-gamma release assay during pregnancy (20-34 weeks' gestation), 6 weeks, and 12 months postpartum by intracellular cytokine staining. We measured overall responses using COMPASS and made comparisons by nonparametric analysis of variance. RESULT: We observed diminished Mtb-specific CD4+ T-cell responses in WLHIV during pregnancy versus 12 months postpartum (COMPASS median functional score [FS] .009 vs 0.12, CONCLUSIONS: Pregnant WLHIV, especially those on IPT, showed reduced Mtb-specific CD4+ T-cell responses. Understanding the impact of pregnancy on Mtb-specific T-cell responses may improve diagnostic approaches.