No increase in adverse birth outcomes with maternal TDF/FTC in US study
Polly Clayden, HIV i-Base
Among pregnant women with HIV in the US, 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 randomised to TDF/FTC/ LPV/r had elevated risk of very preterm birth, very low birth weight, and death compared to those randomised to AZT/3TC/LPV/r.
Data from two large prospective US 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.
|Preterm birth||27 (21.4%)||86 (16.1%)||184 (19.5%)|
|Very preterm birth||5 (4.0%)||26 (4.9%)||44 (4.7%)|
|Low birth weight||30 (23.8%)||86 (16.2%)||175 (18.8%)|
|Very low birth weight||1 (0.8%)||10 (1.9%)||18 (1.9%)|
|Adverse outcome||36 (28.1%)||127 (23.7%)||256 (27.2%)|
|Severe adverse outcome||7 (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 US cohorts.
Rough K et al. TDF/FTC in pregnancy shows no increase in adverse infant birth outcomes in US cohorts. CROI 2017, Seattle. Poster abstract 779.
http://www.croiconference.org/sessions/tdfftc-pregnancy-shows-no-increase-adverse-infant-birth-outcomes-us-cohorts (abstract and poster)