Influence of ovulation inducing drugs and the woman’s age on the results of infertility treatment using assisted reproductive technologies with sperm selection by oocyte-cumulus complexes

Objective: To investigate the effect of ovulation-inducing drugs and woman’s age on the outcomes of infertility treatment using ART with spermatozoa selection by cumulus cells.

Materials and methods: This study included 267 couples undergoing ART for infertility treatment. Clinical and embryological parameters of the ART cycle were assessed. The study group included 130 patients (CC group) with spermatozoa selected by CC and subsequent ICSI procedures. The control group consisted of 137 patients who underwent a standard ICSI procedure with spermatozoa selection based on morphological characteristics (ICSI group). Each group was divided into women under the age of 35 years and those aged 36 years and above. To assess the effect of ovarian stimulation, groups of women were categorized according to the type of trigger for final follicle maturation: human chorionic gonadotropin (hCG) (n=182) and gonadotropin-releasing hormone agonist (GnRH agonist) (n=52). Some women did not undergo embryo transfer (n=33). VitroLife medium (Sweden) was used during the embryological stage. Only one embryo was transferred to the uterine cavity. Statistical analysis was performed using SPSS Statistics software (USA), and included both parametric and non-parametric methods.

Results: Among women aged < 35 years, the absolute number of blastocysts obtained on the 5th day of culture was significantly higher in the CC group than that in the ICSI group (Me 2 (1; 3) and 3 (1; 5), p=0.02). Patients of late reproductive age (≥ 36 years) also showed a significantly higher number of blastocysts on the 5th day of culture when spermatozoa were selected using CC (p=0.03). When evaluating the effect of the trigger of the final follicle maturation, it was found that the embryo implantation rate was significantly higher when hCG was used and sperm were selected by CC (CC 44.9%, ICSI 17.9%, p=0.01); however, the birth rate did not differ significantly, regardless of the age of the woman.

Conclusion: This study shows that the technology of spermatozoa selection using CC in infertility treatment with ART can be successfully implemented in different age groups of women, which will increase the number of embryos at the blastocyst stage suitable for transfer to the uterine cavity and cryopreservation. At the same time, the implantation rate can only be increased in women in whom exogenous hCG is used to trigger the final maturation of oocytes. The data obtained in this study provide hope for the development of more advanced in vitro sperm selection methods that would mimic the physiological conditions in the female reproductive tract.