Efficacy of Hyaluronan-Enriched Transfer Medium in Frozen-Thawed Embryo Transfer: A Retrospective Single-Center University Hospital Study Using a Historical Cohort.

OBJECTIVE: Since 2023, our university hospital has incorporated hyaluronan-enriched transfer medium (HETM) into all frozen-thawed embryo transfers (FETs). This study aimed to evaluate whether HETM improved clinical pregnancy rates in FET, particularly in patients with recurrent implantation failure (RIF). METHODS: We analyzed 368 FET cycles using a conventional hyaluronan-free transfer medium and 358 FET cycles using HETM, in which thawed embryos were incubated for 2-4 h before transfer. The main outcome was clinical pregnancy. Multiple logistic regression was used to evaluate the effectiveness of HETM. RESULTS: The mean age of patients was 37.4 years (standard deviation = 4.2), and RIF, defined as failure to achieve pregnancy after two or more previous embryo transfers, accounted for 51.2%. Clinical pregnancy rates were significantly higher in the HETM group (37.7%) than in the control group (27.2%) (p = 0.002). Stratified analyses showed that HETM was associated with higher clinical pregnancy rates in RIF cycles (adjusted odds ratio = 2.4 [95% confidence interval: 1.4-3.9]). An additional analysis restricted to patients with three or more previous failed embryo transfers showed similar results. CONCLUSION: This study demonstrates HETM use is associated with improved clinical pregnancy rates in FET, particularly in cases of RIF.