Pregnancy Outcomes in HIV-Infected Women Receiving Long-Term Isoniazid Prophylaxis for Tuberculosis and Antiretroviral Therapy

Objective. While 6- to 12-month courses of isoniazid for tuberculosis prevention are considered safe in pregnant women, the effects of longer-term isoniazid prophylaxis or isoniazid in combination with antiretroviral therapy (ART) are not established in human-immunodeficiency-virus-(HIV-) infected women who experience pregnancy during the course of therapy. Design. Nested study of pregnancy outcomes among HIV-infected women participating in a placebo-controlled, TB-prevention trial using 36 months daily isoniazid. Pregnancy outcomes were collected by interview and record review. Results. Among 196 pregnant women, 103 (52.6%) were exposed to isoniazid during pregnancy; all were exposed to antiretroviral drugs. Prior to pregnancy they had received a median of 341 days (range 1–1095) of isoniazid. We observed no isoniazid-associated hepatitis or other severe isoniazid-associated adverse events in the 103 women. Pregnancy outcomes were 132 term live births, 42 premature births, 11 stillbirths, 8 low birth weight, 6 spontaneous abortions, 4 neonatal deaths, and 1 congenital abnormality. In a multivariable model, neither isoniazid nor ART exposure during pregnancy was significantly associated with adverse pregnancy outcome (adjusted odds ratios 0.6, 95% CI: 0.3–1.1 and 1.8, 95% CI 0.9–3.6, resp.). Conclusions. Long-term isoniazid prophylaxis was not associated with adverse pregnancy outcomes, such as preterm delivery, even in the context of ART exposure.