Frequency of Viremic Episodes in HIV-Infected Women Initiating Antiretroviral Therapy During Pregnancy: A Cohort Study.

Background: The numbers of human immunodeficiency virus (HIV)-infected women initiating antiretroviral therapy (ART) in pregnancy are increasing rapidly with global policy changes. There are widespread concerns about ART adherence during pregnancy and postpartum but few data on viral suppression (VS) over time in these populations.
Methods: We followed a cohort of 523 women in Cape Town, South Africa, initiating ART in pregnancy (once-daily tenofovir 300 mg, emtricitabine 200 mg, and efavirenz 600 mg) and achieving VS (<50 copies/mL). Participants provided specimens through 12 months postpartum for batched viral load (VL) testing separate from routine care. Analyses described the incidence of major (>1000 copies/mL) and minor (50-1000 copies/mL) viremic episodes (VEs) and factors associated with major VEs.
Results: In the cohort (median age, 28 years; median pre-ART VL, 3.99 copies/mL; 3% previously defaulted ART; 24% with previous exposure to short-course antiretrovirals), the median time of follow-up from VS was 322 days. Overall, 70% maintained VS throughout follow-up, 8% experienced minor VEs only, and at least 1 major VE was documented in 22% of women. In women with VEs, peak viremia (median, 3.79 log10 copies/mL) was linearly related to pre-ART VL. The incidence of major VEs after initial VS was independently associated with younger age, ART initiation during the third trimester, previous defaulting on ART, and postpartum follow-up. Conclusions: Viremia appears to occur frequently, particularly postpartum, among HIV-infected women after initial VS in this setting. More intensive VL monitoring is warranted in this population; the immediate causes and long-term implications of VE require investigation.