Objective: We evaluated the prevalence of de novo hypertensive disorders of pregnancy (dnHDP) in pregnant people with HIV (PPHIV) in the Western Cape Province, South Africa in 2018-2019 by HIV and antiretroviral therapy (ART) status.

Methods: All people with a pregnancy outcome from 1 January 2018 to 31 December 2019 in the Western Cape Provincial Health Data Centre (WCPHDC) were included. The WCPHDC integrates data from multiple electronic platforms according to unique identifiers. dnHDP was classified by ICD-10 code or first-time prescription of antihypertensive drugs less than 140 days before delivery. Pregnant people with preexisting hypertension without superimposed preeclampsia/eclampsia were not considered to have dnHDP. Adjusted prevalence ratios (aPR) for dnHDP by HIV/ART status were calculated using Poisson regression with robust variance.

Results: Among 180 553 pregnant people studied, 13 677 (7.6%) had dnHDP and 33 978 (18.8%) were PPHIV. Among PPHIV, 11.3% ( N = 3827) had no evidence of ART, 59.7% ( N = 20 283) initiated ART preconception and 29.0% ( N = 9868) had ART initiated during pregnancy. Compared to those without HIV (7.7%), dnHDP prevalence was lower in PPHIV with preconception [6.9%; aPR 0.78; 95% confidence interval (CI) 0.74-0.83] or pregnancy-initiated ART (7.0%; aPR 0.83; 95% CI 0.75-0.92) and higher in PPHIV without ART (9.8%; aPR 1.17; 95% CI 1.06-1.29) adjusted for maternal age, multiparity, multigestation pregnancy and preexisting hypertension. ART duration by delivery of at least 100 weeks versus pregnancy-initiated ART of 20-<40 weeks was protective (aPR 0.88; 95% CI 0.78-0.98).

Conclusions: In the context of universal ART, these findings are reassuring for most PPHIV. ART was not associated with increased dnHDP prevalence and longer ART duration was protective.