Received April 07, 2008
Accepted April 20, 2008

Objective: To evaluate the effect of using an embryos transfer (ET) medium supplemented with hyaluronic acid (HA) on the implantation and pregnancy rates, as well as to compare embryo quality parameters to those rates in advanced aged patients under in vitro fertilization treatment. Methods: Case-control prospective non-randomized study. This study included 128 patients were age ≥35 years who were under in vitro fertilization and ET treatment from January 2004 and June 2005. Group A had 69 cycles with ET medium supplemented with HA and Group B had 59 cycles with medium containing human serum albumin (HSA). Results: There was no significant statistic difference between groups concerning patients’ age (38.6 ± 2.87 years vs. 38.5±2.6 years), number of embryos transferred (161 vs. 157) and number of embryos transferred for each patient (2.33±1.28 vs. 2.66±1.17). Implantation and pregnancy rates in group HA, being 19.3% and 36.2%, respectively, in group HAS, which had implantation rate of 14.6% and pregnancy rate of 32.2%. Conclusion: The medium supplemented with HA presented increase on implantation and pregnancy rates, although with no statistically significant differences. The implantation rate of the ET medium with HA presented no linear tendency related the embryo quality; implantation was independent of embryo quality. The supplementation of HA in the ET medium presented positive effect on the implantation process for advanced aged patients.