High initiation and persistence on pre-exposure prophylaxis (PrEP) in HIV-uninfected pregnant women in Cape Town, South Africa


BACKGROUND: Oral PrEP is a safe and effective prevention strategy to reduce women's risk of HIV in pregnancy and postpartum. Successful PrEP outcomes require PrEP adherence at the time of potential HIV exposure, especially in pregnancy when tenofovir plasma concentrations are lower than postpartum.
METHODS: The PrEP in pregnancy and postpartum (PrEP-PP) study is an ongoing prospective cohort which enrolls consenting pregnant, HIV-uninfected women (>15-years) at first antenatal care visit, followed through 12-months postpartum. Interviewers collect data on participant socio-demographics, relationships, HIV risk factors including: partner's serostatus, intimate partner violence, substance use and depression. At baseline we provided point-of-care STI testing/treatment of chlamydia, gonorrhea and trichomonas (GeneXpert). We evaluate factors associated with: PrEP initiation, PrEP persistence (returning for PrEP repeat prescription) and PrEP adherence (reporting taking PrEP >5 of last 7-days) at 3-months after PrEP start using multivariable logistic regression controlling for baseline age and gestational age.
RESULTS: Between Aug'19 and Oct'20 we enrolled 712 pregnant women (median gestation=21w; median age=26y). Following counseling, 91% of women initiated PrEP at their first antenatal visit (n=649). Women who were married had lowest odds of taking PrEP compared to unmarried women (aOR=0.11; 95%CI=0.02-0.73), though over one-fourth didn't know her partner's serostatus (27%). Thirty-five percent of women were diagnosed with a STI. Those with a STI had a non-significant greater odds of initiating PrEP (aOR=1.60; 95%CI=0.89-2.89). Pregnant women who reported high internalized PrEP stigma had lower odds of initiating PrEP (aOR=0.06; 95%CI=0.03-0.12). At 1m, 72% women returned for a repeat prescription; at 3m, 60% returned. Among those returning at 3m, 87% reported adhering to PrEP in past 7-days. Being postpartum was associated with lower odds of PrEP persistence and adherence (aOR=0.31;95% CI=0.16-0.61) adjusting for follow-up study, maternal and gestational age. Retention was lower in women who reported side-effects (22% of women reported nausea, dizziness and vomiting).
CONCLUSIONS: PrEP uptake was high especially in high-risk women. PrEP persistence and adherence were higher than other SA populations. Anticipated stigma, side effects and the postpartum period presented challenges to optimal PrEP use, pointing to potential targets for interventions to improve PrEP adherence in pregnant/postpartum women.