No Increase in Adverse Birth Outcomes With Maternal TDF/FTC in U.S. Study

Among pregnant women with HIV in the U.S., use of tenofovir, emtricitabine, lopinavir/ritonavir (TDF/FTC/LPV/r) was not associated with increased risk of adverse infant birth outcomes when compared to zidovudine, lamivudine, LPV/r (AZT/3TC/LPV/r) or TDF, FTC, atazanavir/ritonavir (TDF/FTC/ATV/r).

In the PROMISE trial, infants of women randomized to TDF/FTC/LPV/r had elevated risk of very preterm birth, very low birth weight, and death compared to those randomized to AZT/3TC/LPV/r.

Data from two large prospective U.S. cohort studies (IMPAACT P1025 and PHACS ) were used to compare risk of adverse birth outcomes for infants with in utero exposure to AZT/3TC/LPV/r, TDF/FTC/LPV/r, and TDF/FTC/ATV/r. The results from this comparison were shown at CROI 2017.

Exposure was classified by first regimen used during pregnancy. The investigators evaluated the risk of the following outcomes: preterm (<37 weeks) and very preterm (<34 weeks) birth, low (<2,500 g) and very low (<1,500 g) birth weight, composite adverse and severe adverse outcomes (outcomes above plus foetal loss, infant mortality).

Of 4,646 enrolled infants, 128 (2.8%), 539 (11.6%) and 954 (20.5%) had mothers who received TDF/FTC/LPV/r, TDF/FTC/ATV/r and AZT/3TC/LPV/r respectively. Table 1 shows risk of outcomes by initial ART regimen.

Table 1. Risk of Outcomes by Initial ART Regimen in Pregnancy
Preterm birth27 (21.4%)86 (16.1%)184 (19.5%)
Very preterm birth5 (4.0%)26 (4.9%)44 (4.7%)
Low birth weight30 (23.8%)86 (16.2%)175 (18.8%)
Very low birth weight1 (0.8%)10 (1.9%)18 (1.9%)
Adverse outcome36 (28.1%)127 (23.7%)256 (27.2%)
Severe adverse outcome7 (5.5%)28 (5.2%)51 (5.4%)

In crude and adjusted analyses, the investigators found TDF/FTC/LPV/r was not associated with adverse birth outcomes compared to AZT/3TC/LPV/r or TDF/FTC/ATV/r. The study was underpowered to evaluate severe outcomes. TDF/FTC/LPV/r use in pregnancy was uncommon in the two large U.S. cohorts.


Rough K et al. TDF/FTC in pregnancy shows no increase in adverse infant birth outcomes in U.S. cohorts. 24th Conference on Retroviruses and Opportunistic Infections (CROI 2017), 13-16 February 2017, Poster abstract 779. (abstract and poster)