Three different regimens of antiretroviral therapy did not produce significantly different adverse birth outcomes in women with HIV despite previous research showing an increased risk in premature birth or death in infants after a regimen of tenofovir, emtricitabine, and ritonavir-boosted lopinavir therapy, according to a recent analysis of two multicenter cohort studies published in the New England Journal of Medicine.

Kathryn Rough, ScD, of the Brigham and Women’s Hospital and Harvard Medical School in Boston and colleagues analyzed 4,646 birth outcomes in the SMARTT (NCT01310023) and P1025 (NCT00028145) trials from 3,847 unique women who received tenofovir, emtricitabine, and ritonavir-boosted lopinavir (TDF–FTC–LPV/r), zidovudine, lamivudine, and ritonavir-boosted lopinavir (ZDV–3TC–LPV/r), or TDF–FTC with ritonavir-boosted atazanavir (ATV/r) during gestation. There were 954 infants or fetuses exposed to ZDV–3TC–LPV/r (20.5%), 539 infants or fetuses exposed to TDF–FTC–ATV/r (11.6%), and 128 infants or fetuses exposed to TDF–FTC–LPV/r (2.8%), with 4,480 singleton, 80 twin, and 2 triplet pregnancies.

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“TDF–FTC–LPV/r was rarely used by pregnant women with HIV infection in either U.S.-based cohort, and its use in other settings is also limited, because it is not among the first-line regimens recommended by the WHO,” Dr. Rough and her colleagues wrote in their study (N Engl J Med 2018;378:1593-603).

“Concerns regarding the use of TDF–FTC–LPV/r during pregnancy remain; further investigation is warranted to understand why women who initiated TDF–FTC– LPV/r before conception had higher risks of preterm birth, low birth weight, and any adverse outcome than women who initiated ZDV–3TC– LPV/r or TDF–FTC–ATV/r before conception in subgroup analyses.”

Overall, there was a premature birth risk between 16.1% and 21.4% and a low birth weight risk between 16.2% and 23.8% across all antiretroviral therapy regimens, with an overall adverse outcome rate between 23.7% and 28.1%. For women who received TDF–FTC–LPV/r, there was a risk ratio of 0.90 (95% confidence interval, 0.60-1.33) for preterm births, 1.13 for low birth weight (95% CI, 0.78-1.64) and 0.92 for any adverse outcome (95% CI, 0.67-1.28) compared with women who received ZDV–3TC–LPV/r.

“For the outcomes of preterm birth, low birth weight, and any adverse outcome, TDF–FTC–ATV/r appeared to have lower risks than the LPV/r-based regimens; however, many of these associations were not significant,” the authors wrote.

Women who received TDF–FTC–LPV/r had a risk ratio of 1.14 (95% CI, 0.75-1.72) and a low-birth-weight risk ratio of 1.45 (95% CI, 0.96-2.17), compared with women who received TDF-FTC-ATV/r. Regarding very-low-birth-weight and very-preterm birth, the researchers noted no significant differences among regimen groups.

One author reported stock from Abbott, AbbVie, Novartis, and Roche outside the submitted work; one author reported personal fees from Boehringer-Ingelheim; and five authors reported grants from pharmaceutical companies and Google outside the submitted work.

SOURCE: Rough K et al. N Engl J Med 2018;378:1593-603.

Antiretroviral choice for pregnant women with HIV does not appear to impact birth outcomes