by Carolyn Chu, MD, MSc, AAHIVS, AAHIVM Chief Medical Officer

March 28, 2023

Featured Literature:

Moodley D, Lombard C, Govender V, et al. Pregnancy and neonatal safety outcomes of timing of initiation of daily oral tenofovir disoproxil fumarate and emtricitabine pre-exposure prophylaxis for HIV prevention (CAP016): an open-label, randomised, non-inferiority trial. Lancet HIV. 2023 Mar;10(3): e154-e163. PMID: 36746169.   

CAP016 was an open-label trial conducted at a single hospital-based research site in Durban. Eligible pregnant adults at 14-28 weeks’ gestation at time of enrollment were assigned to either immediate PrEP initiation during pregnancy or deferred PrEP initiation at breastfeeding cessation. Enrollment started in September 2017 but was stopped in December 2019 when South Africa’s PrEP guidelines expanded to include pregnant people in the national roll-out. 540 women were ultimately enrolled (271 randomized to immediate PrEP and 269 to deferred PrEP). Median timing for PrEP start in the ‘immediate initiation’ group was 19 weeks’ gestation, with median time on study from randomization to delivery of 19.7 weeks. Mean calculated adherence was 87% at 4 weeks, 93% at 8 weeks, 94% at 12 weeks, and 95% at 16 weeks after PrEP initiation—nausea and vomiting in the first month (11%) as well as headache (14%) were reported as reasons for missed doses. Immediate PrEP initiation was not associated with preterm birth or small for gestational age birth. Investigators were unable to determine non-inferiority for less frequent outcomes (e.g., very preterm birth, low birthweight, very low birthweight, and stillbirth). No renal function abnormalities were observed. Four maternal HIV seroconversions were observed: 3 in the immediate PrEP group between 27 weeks and 35 weeks gestation, and 1 in the deferred PrEP group at 32 weeks gestation. All four neonates tested negative for HIV within 14 days of birth.

Author’s Commentary:

These study findings add to existing evidence suggesting that tenofovir disoproxil fumarate and emtricitabine can be safely used in pregnancy, specifically that PrEP initiation does not increase occurrence of preterm birth, small for gestational age, or any adverse pregnancy outcome. Participants did not experience renal toxicity (changes in maternal and infant bone mineral density, and infant growth parameters will be reported separately). Of note, nausea/vomiting and headache were relatively common after PrEP initiation – these may be important considerations when offering PrEP to pregnant people and also during early follow-up assessments of medication tolerability and adherence. As providers gain experience with PrEP and pregnancy, best and promising practices regarding HIV testing, timely communication with labor and delivery units, and postpartum/postnatal follow-up (including breastfeeding considerations) should be identified and disseminated. 

The author has no conflicts of interest to disclose.

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