Hoffman RM, Warshaw MG, Amico KR, et al. - Given the high rates of viremia among HIV-infected, postpartum women on antiretroviral therapy (ART), researchers sought for predictors of postpartum viremia (defined as 2 consecutive viral loads > 1000 copies/mL after 24 weeks on ART) in the PROMISE study. They randomized women with pre-ART CD4+ T-cell counts ≥ 400 cells/mm³ who started ART during pregnancy postpartum to either continue ART (CTART) or discontinue ART (DCART). The CTART arm comprised 802 women; median age at entry 27 years and median CD4+ T-cell count 696 cells/mm³. They identified 175 women in CTART with viremia (22%). Missed ART doses within the past 4 weeks, younger age, shorter duration of preentry ART, and being from the South American/Caribbean region were identified as predictors of viremia. Therapy reinitiated in 137 women in DCART; among these, the probability of viremia was similar to CTART (0.24 by week 96; 0.27 by week 144). Findings suggest high rates of postpartum viremia and higher frequency of viremia in younger postpartum women who start ART later in pregnancy. They recommend implementing interventions targeting these higher-risk women.