EXPOSURE TO HIV PRE-EXPOSURE PROPHYLAXIS IN PREGNANCY AND PERINATAL OUTCOMES AMONG WOMEN IN WESTERN KENYA

Abstract

Introduction: While existing safety data on prenatal PrEP use are reassuring, there is a need for continued surveillance, especially among women who initiate PrEP outside research settings. We analyzed data from three recent PrEP safety and/or implementation studies that enrolled women who initiated PrEP within routine health clinics in Western Kenya to summarize perinatal outcomes following PrEP exposure in pregnancy. Methods: We utilized data from participants in PrIMA, PrIMA-X, and mWACh-PrEP studies who were ≥ 15 years, HIV negative, remained pregnant until at least 24 weeks gestation, and enrolled ≤32 weeks gestation. We summarized frequency of and compared each pregnancy outcome (stillbirth, preterm birth, low birthweight, neonatal death, congenital anomalies) by study cohort, PrEP exposure status (any vs. none), and timing of first PrEP exposure (first-, second-, or third-trimester exposure). In exploratory analyses, Poisson regression models were used to test whether timing of first PrEP exposure, timing of PrEP initiation (prior to pregnancy vs. during pregnancy), and duration of exposure in pregnancy were associated with adverse outcomes, adjusting for maternal age, primigravity, and clustered by study cohort as a random effect. Results: Data from 4,389 women were included in the analysis (29.8% with PrEP exposure). The median age was 24.1 years (IQR: 21.0, 28.6), and median gestational age at enrollment was 24 weeks (IQR: 20, 28). Most women (83.4%) were married and 39.4% had a partner of unknown HIV status. Among PrEP-exposed pregnancies (n=1310), most initiated PrEP in the second trimester (56.2%). Compared to pregnancies without PrEP exposure, preterm birth was less frequent among those with PrEP exposure in the first trimester (adjusted prevalence ratio [aPR]=0.49, 95% CI 0.42-0.57) and third-trimester (aPR=0.74, 95% CI 0.61-0.88) in exploratory analyses. Low birthweight was also lower among pregnancies with any PrEP exposure (aPR=0.77, 95% CI 0.61-0.97) and third-trimester exposure (aPR=0.74, 95% CI 0.61-0.88) compared to those with no exposure. Frequency of all other perinatal outcomes was comparable between pregnancies with and without PrEP exposure and did not differ by timing of exposure. Conclusion: We found no appreciable differences in perinatal outcomes by PrEP exposure, though PrEP-exposed pregnancies had lower frequency of some adverse outcomes. These findings support current guidelines recommending PrEP for pregnant and lactating women at risk of HIV.