INTRODUCTION
The choice of enzymes to free the oocyte from cumulus cells before the ICSI procedure can have a significant impact on the quality of the oocyte itself and the subsequent development of the embryo. It is assumed that the use of recombinant human hyaluronidase will have a more sparing effect when ruptured gap junctions between the oocyte and cumulus cells and the exposure time in the enzyme will not limit the quality of the egg cell.
OBJECTIVE
Evaluation the effect of the type of enzyme used for denudation of oocyte-cumulus complexes on the formation of blastocysts and the pregnancy rate.
MATERIAL AND METHODS
The study included 252 cycles of IVF-ICSI and 433 cycles of IVF (control group). The patients were randomly divided into 2 experimental groups according to the method of denudation of oocyte-cumulus complexes: in group 1 — bovine hyaluronidase was used (n=112), in group 2 — human recombinant hyaluronidase was used (n=140). Further, the patients were allocated four age groups: up to 30 years (195 women), 31—35 years (204 women), 36—38 years (233 patients) and older than 39 years (53 people). In each age group, an analysis of the effectiveness of the ART cycles was carried out according to embryological indicators: the level of fertilization, blastulation, the formation of good quality blastocysts and the pregnancy rate.
RESULTS
The using of recombinant hyaluronidase did not affect the level of fertilization and the frequency of blastulation in all treatment groups. Patients 36—38 years old showed a statistically significant increase in pregnancy rate when using recombinant human hyaluronidase compared with the experimental group where bovine hyaluronidase was used (64.0% versus 48.6%; p<0.05). It has been shown that ICSI technique significantly increased the pregnancy rate in the treatment of women over 39 years old. Also, in this age category of patients, an increase in the level of formation of good quality blastocysts was detected during denudation of oocyte-cumulus complexes using recombinant hyaluronidase by 19% (0.12±0.22 versus 0.31±0.35; p<0.05).
CONCLUSION
Recombinant hyaluronidase did not affect oocyte fertilization rate, blastulation rate and pregnancy rate. Two age categories of patients were identified in which the use of recombinant hyaluronidase may have advantages: patients 36—38 years old had a higher pregnancy rate, and women 39 years old and older had a higher frequency of receiving top-quality blastocysts.
