Isoniazid Therapy Safe for Preventing Tuberculosis in HIV-Infected Pregnant Women: Presented at CROI

By Alex Morrisson

SEATTLE, Wash -- March 8, 2019 -- Isoniazid therapy appears to be safe for both mothers-to-be and their infants in the prevention of tuberculosis in women who are pregnant and have been diagnosed with HIV, according to results of a study presented here at the 2019 Conference on Retroviruses and Opportunistic Infections (CROI).

“These results held true even after we accounted for other factors for worse outcomes, such as advanced HIV, advanced maternal age, and low weight gain during pregnancy,” stated Nicole Salazar-Austin, MD, Johns Hopkins Medicine, Baltimore, Maryland, on March 6.

Pregnancy and HIV both increase the risk of tuberculosis.

Dr. Salazar-Austin and colleagues extracted patients from the prospective real-world Tshepiso Study from Soweto, South Africa (2011-2014), which evaluated maternal and infant outcomes among pregnant women living with HIV with and without active tuberculosis. Isoniazid prevention therapy was initiated by public antenatal and HIV clinics and not by the study.

The current observational analysis includes 151 women with known pregnancy outcomes; 69 (46%) reported initiating isoniazid preventive therapy during pregnancy.

The researchers observed adverse pregnancy outcomes in 16% of the HIV-infected women on isoniazid versus 28% of women who were not on isoniazid prevention therapy (P = .08), a difference that was not significant.

Maternal or foetal or infant death or tuberculosis occurred in 2 women in the isoniazid prevention therapy group versus 3 women who were not on the therapy (P = 1.00), essentially demonstrating no safety difference.

No infant developed tuberculosis.

One women who was not on preventive therapy was diagnosed with tuberculosis; 1 woman in the preventive therapy arm died during the trial. Foetal demise or stillbirth occurred once in each arm of the study.

There was a trend toward a greater number of premature births in the women not on preventive therapy than in those on prevention therapy (n = 18 vs 10; P = .06).

Maternal and infant hospitalisations were not different statistically.

“We believe that these results will provide some reassurance that isoniazid preventive therapy may be used in the second or third trimester of pregnancy among women with HIV in high-prevalence settings,” concluded Dr. Salazar-Austin.

More research is required to evaluate isoniazid prevention therapy and to evaluate some of the new tuberculosis preventive therapies, noted the researchers.

[Presentation title: IPT and Pregnancy Outcomes in HIV-Positive Women: The Tshepiso Cohort. Abstract 77]

To read more Conference Dispatch articles, click here.