(633) HIV viral suppression in sequential pregnancies with and without changing antiretroviral therapy class

Recommended antiretroviral therapy (ART) in pregnancy has evolved. We evaluate viral suppression in patients who change medication classes between sequential pregnancies. We hypothesize that patients who remain on the same ART classes have improved viral suppression in the subsequent pregnancy compared to patients who switch ART classes.

Study Design: We prospectively studied patients with two sequential pregnancies referred to a centralized clinic for HIV management and prenatal care, and who delivered at a single urban, public hospital. Demographics and HIV disease characteristics were compared. The primary outcome was viral suppression (viral load < 50 copies/mL) at presentation of the subsequent pregnancy. We compared patients with the same versus different ART medication classes at delivery of the index and presentation of the subsequent pregnancy. Primary analysis included all pregnancies regardless of ART adherence; subanalysis was restricted to pregnancies on ART at both times.

Results: From January 2011 through December 2021, 116 patients and 232 pregnancies met inclusion criteria. Years since HIV diagnosis were higher in patients who did not change ART classes (Table 1). Compared to 28 (67%) of 42 patients on the same ART classes, 33 (45%) of 74 patients on different ART classes achieved viral suppression at the subsequent pregnancy (p = 0.04). After adjusting for years since HIV diagnosis at the index pregnancy, odds of subsequent pregnancy viral suppression were significantly higher among those who remained on the same ART classes (aOR 1.23; 95% CI, 1.02-1.50) (Table 2). When analysis was restricted to 79 patients on ART at both index delivery and subsequent pregnancy presentation, this difference was no longer significant (aOR 0.97; 95% CI, 0.79-1.19).

Conclusion: For pregnant patients living with HIV, stability in ART class between pregnancies is associated with improved viral suppression in subsequent pregnancies and may be particularly important for those with ART adherence challenges.