Viral Load Testing Practices Among Pregnant People Living With HIV on Admission From Obstetrical Triage

Routine viral load (VL) testing is recommended for pregnant people living with HIV (PLWH) to confirm viral suppression antenatally. The exact timing of this varies in practice. To obtain an up-to-date VL immediately prior to delivery, our institution implemented a policy to test VLs for all pregnant PLWH on admission. Our objective was to characterize testing practices since implementation.

Retrospective chart review of all pregnant PLWH admitted through obstetrical triage at St. Michael's Hospital in Toronto, Ontario from January 2013 to December 2022. Outcomes of interest included VL completion status, stratified by year and other competing admission tasks.

This study identified 135 admissions. The majority had VLs ordered (61.5%) and drawn (85.9%) on admission. VL ordering improved over the latter half of the study period (44.6% vs. 82.0%, P < 0.001). More VLs were ordered among Group B Streptococcus-negative patients (71.3%) compared to positive (41.4%) (P = 0.031) and among those who received an epidural (74.2% vs. 50.7%, P = 0.020). More VLs were drawn by nurses among patients who delivered during the admission (90.9% vs. 42.9%, P < 0.001) and patients who received an epidural (93.5% vs. 79.5%, P = 0.019).

While the rate of ordering VLs improved over the course of the study, the rate of drawing VLs remained high throughout, indicating that nurses consistently drew the bloodwork irrespective of an actual order. VL testing improved with the introduction of pre-printed orders, and varied by Group B Streptococcus status, epidural usage, and delivery status. These findings offer opportunities to guide future clinical practices on antenatal VL testing.