Over the past decade, data have suggested that antiretroviral therapy (ART) may be associated with an increased risk for adverse pregnancy outcomes, namely, preterm birth (PTB). But a combination of methodologic challenges, demographic gaps, and spotty clinical data has left the question unresolved, especially for pregnant women with HIV who reside in developed countries.
“Given that a lot of the emerging data has come out of resource-limited settings where patient and clinical characteristics are different from developed world settings like the United States, we felt that this was an important question to address,” Kartik Venkatesh, MD, PhD, a high-risk obstetrician and perinatal epidemiologist at the Ohio State Wexner Medical Center, Columbus, told this news organization.
In a prospective cohort study of U.S. women with or at risk for HIV, Dr. Venkatesh and his colleagues found that ART exposure (including highly active antiretroviral therapy [HAART]) was associated with as much as an 80% decline in the likelihood of PTB (defined as birth less than 34 weeks). The study was published in HIV Medicine.
24 years of data analyzed
Dr. Venkatesh and his team analyzed self-reported birth data of women with singleton live-born pregnancies enrolled in the ongoing, multicenter, prospective observational Women’s Interagency HIV Study (WIHS) from Oct. 1, 1995, to March 31, 2019.
“We first looked at women with HIV versus without HIV, [who were] matched on many clinical and sociodemographic characteristics and at similarly high risk of some of these obstetrical outcomes like PTB,” explained Dr. Venkatesh. “We then looked at the relative impact of antiretroviral therapy amongst women living with HIV compared to no antiretroviral therapy.”
ART regimens were classified as none, monotherapy, dual therapy, or HAART. (HAART was defined as more than three antiretrovirals, including at least one protease inhibitor [PI], nonnucleoside reverse transcriptase inhibitor, integrase inhibitor, or entry inhibitor.) In this cohort, for 63.5% of women receiving ART, therapy was initiated before pregnancy (mean duration of HAART, 6 years), and most were virally suppressed.
Among the 4,944 women assessed in the WIHS trial, 74% (3,646) had HIV. In total, 383 women had 488 singleton deliveries, including 218 women with HIV (272 deliveries) and 165 without HIV (216 deliveries). Sociodemographics in both cohorts were well matched. For most participants, the mean age was 40-41 years at delivery, most were non-Hispanic Black persons, and the mean pregnancy body mass index was greater than or equal to 29 kg/m2. Of the women with HIV, 33% had chronic hypertension; of those without HIV, 42.1% had chronic hypertension; 4.7% and 5.0%, respectively, had pregestational diabetes.
The findings showed that PTB risk less than 34 weeks was similar between women with (10%) and without (8%) HIV (adjusted risk ratio, 1.30; 95% confidence interval, 0.74-2.31). Among deliveries to women with HIV who were receiving ART, PTB risk less than 34 weeks was lower with HAART (7%), compared with not receiving ART (26%) (aRR, 0.19), as well as with monotherapy or dual therapy (3% vs. no ART) (aRR, 0.12). Notably, 67% of deliveries to women receiving HAART included a PI-containing regimen, but these women were not significantly more likely to have a PTB less than 34 weeks, compared with women taking non-PI HAART regimens (aRR, 2.61; 95% CI, 0.65-10.59). Results were similar for secondary outcomes (PTB less than 28 weeks, less than 37 weeks).