A randomized clinical trial comparing recombinant hyaluronan/recombinant albumin versus human tubal fluid for cleavage stage embryo transfer in patients with multiple IVF-embryo transfer failure

Background: We aimed to examine the efficacy of using an embryo transfer medium enriched with hyaluronan (HA) to improve implantation in a selected group of patients aged <43 years with repeated (>4) implantation failures after IVF-embryo transfer. METHODS About 101 patients, meeting our selection criteria, were randomly allocated to undergo embryo transfer either using our routine embryo transfer medium without HA (control group) or a HA enriched commercial embryo transfer medium (study group). The primary outcome was clinical pregnancy rate. Results: After a similar treatment protocol, the ovarian hormonal response, the mean number of ova retrieved and injected per patient, fertilization and cleavage rates and mean embryo quality were comparable between the study and control groups. Although a similar number of embryos was transferred in both groups (3.1 ± 0.7 versus 2.9 ± 0.6, mean ± SD), a significantly higher implantation rate (16.3% versus 4.8%, P = 0.002) and clinical pregnancy rate (35.2% versus 10.0%, P = 0.004) and delivered or ongoing pregnancy rate (31.3% versus 4.0%, P = 0.0005) were observed in the study group. When mean implantation rate per patient was calculated, the difference between the study (0.148 ± 0.23) and control (0.04 ± 0.13) group was significant (P = 0.003). Conclusions: In this selected group of patients after multiple IVF-embryo transfer failures, the use of HA enriched embryo transfer medium is beneficial.