Antiretroviral adherence among people living with HIV during the postpartum period: a retrospective cohort study at a PMTCT reference center in Rio de Janeiro before and during the COVID-19 pandemic.

Despite success in achieving viral suppression during pregnancy in people living with HIV (PLWH), postpartum adherence remains a challenge. We aimed to describe rates of adherence at a Prevention of Mother-to-Child HIV Transmission (PMTCT) Center before and during the COVID-19 pandemic. This study was conducted from a cohort of PLWH who received prenatal care and were virally suppressed near delivery. We tracked combined antiretroviral therapy (cART) pickups for 12 months and HIV viral load (VL) from 2 to 12 months after delivery. We defined flexible adherence as a monthly pickup of cART and strict adherence as also having VL < 200 copies/mL and at least one maternal HIV VL between two and twelve months postpartum. Pre-pandemic was defined as delivery from March 2017-February 2019 and pandemic as March 2020-February 2022. During the study, 1119 PLWH were followed, and 965 (86%) were suppressed near delivery. There were 511 pre-pandemic and 290 pandemic participants. Adherence rates were 66/511 (13%) and 38/290 (13%), respectively. During the pandemic, more participants conceived using cART and were undetectable at the start of prenatal care; nevertheless, postpartum adherence was no better than pre-pandemic underscoring the need to improve strategies for adherence specific to this subset of PLWH in the postpartum period.