Tuberculosis Preventive Therapy Heightens Risk of Adverse Outcomes in Pregnant Women With HIV

Study findings published today in The New England Journal of Medicine may help guide safe prevention of tuberculosis (TB) in women with HIV who are pregnant or who have recently given birth and live in an area where TB is highly prevalent.

The findings indicate that the initiation of the TB preventive therapy isoniazid during pregnancy carries greater risk than initiation of the treatment during the postpartum period. While the safety of the treatment was similar for women whether they began taking it during pregnancy or 12 weeks after delivery, there was a significantly greater risk of poor health outcomes and death for fetuses and newborns if isoniazid was initiated during pregnancy rather than 12 weeks after delivery.

One or more poor health outcomes, which included stillbirth, spontaneous abortion, low birth weight, preterm delivery, and congenital abnormalities, were documented in 24% of pregnancies of women who began taking isoniazid during pregnancy and in 17% of pregnancies of women who began treatment after delivery.

The findings have important implications, as historically, medical experts have agreed that there is a net benefit to treating active TB during pregnancy and providing isoniazid to prevent active TB in people living with HIV. Currently, World Health Organization guidelines recommend that pregnant women with HIV take isoniazid based on data from nonpregnant adults.

“Pregnant women are often excluded from clinical research, which leads to an information gap that can pose a danger to maternal and infant health,” said Anthony S. Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, in a statement. “The findings reported today give women, health-care providers and policy makers high-quality data for weighing the risks and benefits of TB preventive therapy for pregnant women living with HIV who are taking antiretroviral therapy.”

The study enrolled 956 pregnant women aged 18 years or older who were living with HIV and were 14 to 34 weeks pregnant. None of the women had suspected TB, recent TB exposure, or TB treatment for more than 30 days in the year prior.

Women who began taking isoniazid during pregnancy received 300 mg of the treatment for 28 weeks and then received placebo until 40 weeks following delivery. Other women received placebo until 12 weeks after delivery when they then received 300 mg of isoniazid to take for 28 weeks.

Altogether, 15% of women in the study either experienced serious side effects or stopped taking isoniazid because the side effects. Rates between the 2 groups were not statistically significant.

Reference

Gupta A, Montepiedra G, Aaron L, et al. Isoniazid preventive therapy in HIV-infected pregnant and postpartum women [published online October 3, 2019]. N Engl J Med. doi: 10.1056/NEJMoa1813060.