Current recommendations for women using PrEP who become pregnant include counseling with the choice to continue or discontinue PrEP. However, safety data from women using PrEP throughout pregnancy are very limited.
In an open-label delivery study of PrEP integrated with ART for high risk HIV serodiscordant couples in Kenya and Uganda (the Partners Demonstration Project), women who became pregnant while using PrEP were counseled and offered the opportunity to continue using PrEP throughout pregnancy. Using age-adjusted generalized estimating equations with a logistic link, we compared birth outcomes from babies with exposure to FTC/TDF PrEP throughout pregnancy to those without any exposure, using data from the placebo arm of the Partners PrEP Study clinical trial, which was conducted in the same setting.
Women in the open-label study who became pregnant were a median of 25.8 years (interquartile range [IQR]: 21.0-28.8) and had 2 (IQR: 1-2) children prior to study engagement. Of 34 who became pregnant while using PrEP, 30 (88%) elected to continue PrEP use. Objective adherence measures indicated at least two-thirds of expected doses were taken: a median of 71% of days (IQR: 28%-93%) had a pill bottle opening recorded via MEMS caps and 74% (116/156) of plasma samples collected from women during pregnancy had tenofovir detected, including 35% (54/156) with >40ng/ml detected. Birth outcomes from these pregnancies were compared with 96 pregnancies occurring among 88 women in the Partners PrEP Study clinical trial (median age=28 (IQR: 24.5-33.0), children=3 (IQR: 2-5)). There was no increase in the frequency of pregnancy loss (16.7% PrEP-exposed versus 32.3% PrEP-unexposed, adjusted odds ratio [aOR]=0.29, 95% CI 0.17-1.52) or preterm delivery (0 versus 7.7%, [aOR]=0.4 (0-2.32), exact p=0.4). No congenital anomalies occurred among PrEP-exposed babies.
To our knowledge, these are the first data to report birth outcomes from a study where women used PrEP throughout pregnancy and compare to a similar cohort without PrEP exposure. PrEP-exposed pregnancies had similar rates of pregnancy loss and preterm delivery to PrEP-unexposed women. These data provide some reassurance that PrEP use can safely continue during pregnancy.