Adherence challenges with daily oral pre‐exposure prophylaxis during pregnancy and the postpartum period in South African women: a cohort study

Abstract

Abstract Introduction Daily oral pre‐exposure prophylaxis (PrEP) can reduce HIV acquisition. However, prevention effectiveness requires daily adherence prior to and during periods of sexual activity. Little is known about pharmacologic measures of PrEP adherence during pregnancy and postpartum and the factors related to optimal adherence during periods of sexual activity in this population. Methods Between August 2019 and October 2021, we enrolled pregnant women without HIV at their first antenatal care visit followed‐up through 12 months postpartum. Eligible women ≥16 years old received HIV prevention counselling and were offered oral PrEP (TDF‐FTC). We quantified tenofovir‐diphosphate (TFV‐DP) in dried blood spots in women who reported taking PrEP in the past 30 days (at quarterly follow‐up visits). We used regression models with generalized estimating equations to evaluate correlates of TFV‐DP (any vs. none, and ≥2 vs. 5/month vs. no sex or <5 times/month = 2.11; 95% CI = 1.58–2.82) adjusting for age and pregnancy versus postpartum status. TFV‐DP concentrations declined over follow‐up time (aOR for 6 vs. 3 months = 0.49; 95% CI = 0.36–0.67). Conclusions Objectively measured adherence to PrEP was low overall and did not correlate with self‐reported use. There is an urgent need for objective adherence measures to support clinical decision‐making as well as adherence support interventions as part of PrEP services for pregnant and postpartum women at risk of HIV.

Keywords

• adherence
• breastfeeding
• pre‐exposure prophylaxis
• pregnant
• PrEP
• South Africa