SEATTLE — Initiating isoniazid preventive therapy for tuberculosis during pregnancy is not associated with a higher rate of poor maternal or infant outcomes, according to observational results from the Tshepiso study presented at CROI.
Nicole M. Salazar-Austin, MD, assistant professor of pediatrics at the Johns Hopkins University School of Medicine, and colleagues noted that research has shown pregnancy and HIV raise the risk for TB, and that the disease can result in poor maternal and infant outcomes. A previous randomized trial, IMPAACT P1078, found that isoniazid preventive therapy (IPT) during pregnancy resulted in a higher risk for adverse maternal and neonatal outcomes compared with IPT after delivery, raising questions about its use.
Tshepiso was a prospective cohort study evaluating maternal and infant outcomes among pregnant women with HIV, with and without active TB, Salazar-Austin and colleagues noted. From January 2011 through January 2014 in Soweto, South Africa, they followed mother and infant pairs through 1 year of life.
As part of the observational study, Salazar-Austin and colleagues analyzed the impact of initiating or not initiating IPT during pregnancy on maternal and infant outcomes among pregnant women with HIV without active TB.
The analysis included 151 women, of whom 46% reported initiating IPT during pregnancy. At enrollment, the median age of the participants was 29 years and their median CD4 count was 373 cells/mm3 among women on IPT compared with 29 years and 364 cells/mm3 among women not on IPT. According to Salazar-Austin and colleagues, 66% of women on IPT also were on ART compared with 78% of women not receiving IPT. Of the women on IPT, 85% were being treated with efavirenz compared with 83% of women not on IPT.
During pregnancy, 40% of women receiving IPT had a viral load less than 20 copies/mL compared with 56% of women not on IPT (P = .004).
Among women exposed to IPT during pregnancy, the researchers observed a lower proportion of poor birth outcomes compared with unexposed women, 16% vs. 28%.
“This was true even after we accounted for other reasons for poor birth outcomes such as advanced HIV disease, advanced maternal age and low weight gain during pregnancy,” Salazar-Austin said during a news conference.
However, they noted that the study was not designed to analyze the effect of IPT on pregnancy outcomes, and that more research into the safety of IPT for pregnant women with HIV is warranted.
“We’re hoping that these results will provide some reassurance that isoniazid preventive therapy can be used in the second or third trimester of pregnancy among women living with HIV in high-burden settings,” Salazar-Austin said. “Certainly, more research is needed to evaluate IPT but also to evaluate some of the new TB preventive therapy regimens including 12 weekly doses of rifapentine and isoniazid (3HP) and one-month daily rifapentine and isoniazid (1HP) for pregnant women living with HIV.” – by Marley Ghizzone
Salazar-Austin N, et al. Abstract 77. Presented at: Conference on Retroviruses and Opportunistic Infections; March 4-7, 2019; Seattle.
Disclosure: Salazar-Austin reports no relevant financial disclosures.