No increase in adverse birth outcomes with maternal TDF/FTC in US study
27 February 2017. Related: Conference reports, Pregnancy, CROI 24 (Retrovirus) 2017.
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.
| 1st regimen | TDF/FTC/LPV/r | TDF/FTC/ATV/r | AZT/3TC/LPV/r |
|---|---|---|---|
| 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.
Reference:
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)