Factors associated with HIV viral load control in the early postpartum period - a Canadian prospective cohort study.

Despite success in managing HIV during pregnancy, challenges remain around sustained adherence with antiretroviral therapy (ART), and the suboptimal viral load (VL) suppression during the postpartum period. The objective of this study was to compare VL levels at delivery and during the postpartum period and assess factors associated with lack of viral suppression during the postpartum period in Canada. We combined data from two Canadian prospective cohorts, which included 286 HIV-positive women (352 pregnancies) who delivered between 2012 and 2020. Delivery VL, postpartum VL, and potential factors associated with an undetectable VL (<50 copies/mL), 2-18 weeks after delivery were assessed. To account for the correlation between multiple pregnancies from the same woman, generalized estimating equations were used to assess bivariate associations. Ninety-nine per cent of pregnant women were on ART during pregnancy compared to 93% during the postpartum period. Of those with available VL results ( n  = 214 pregnancies), 94% of women achieved an undetectable VL at delivery compared to 87% during the postpartum period. The postpartum period is a challenging time for ART use and VL control. Qualitative studies are needed to better understand these challenges and guide us in designing adequate interventions.