RESUMO
OBJECTIVE: To compare the effects of hyaluronic acid (HA)-enriched transfer medium versus standard medium on live birth rate after frozen embryo transfer (FET). DESIGN: Randomized, double-blind, controlled trial. SETTING: Two tertiary fertility centers. PATIENT(S): Infertile women aged <43 years at the time of in vitro fertilization undergoing FET. INTERVENTION(S): The women were randomly assigned to 2 groups in a 1:1 ratio. The HA group used EmbryoGlue (Vitrolife, Gothenburg, Sweden) with an HA concentration of 0.5 mg/mL, while the control group used supplemented G-2 (Vitrolife) medium with an HA concentration of 0.125 mg/mL. MAIN OUTCOME MEASURE(S): Live birth rate. RESULT(S): Five hundred fifty women were recruited from April 2016 to April 2018 and included in the intention-to-treat analysis. Eight women in the HA group and 5 women in the control group did not undergo FET because the embryos did not survive on thawing. One woman in the HA group cancelled FET because of fever. One woman in the HA group withdrew and received conventional medium. The 2 groups were similar in demographic characteristics. The live birth rates in the HA group and the control group were comparable (25.5% vs. 25.8%; relative risk 0.99; 95% confidence interval 0.74-1.31). The other clinical outcomes were also similar between the 2 groups. Logistic regression showed that the type of transfer medium was not associated with live birth. CONCLUSION(S): The use of HA-enriched transfer medium does not improve the live birth rate of FET compared with standard medium. TRIAL REGISTRATION NUMBER: NCT02725827 (ClinicalTrials.gov).