The results of infertility treatment with assisted reproductive technology and sperm selection via cumulus-oocyte complexes

During in vivo fertilization, human spermatozoa need to pass through cumulus-oocyte complex (COC), to cross the zona pellucida, and then penetrate into the oocyte for completion of fertilization. For this reason, COC plays an important role in physiological selection of functionally competent male gametes.

Objective: Assessment of the clinical effectiveness of using cumulus cells for sperm selection during intracytoplasmic sperm injection into the oocyte (ICSI) in cases of impaired spermatogenesis in the population of the Russian married couples, who underwent infertility treatment using assisted reproductive technology (ART).

Materials and methods: The study included 267 married couples, who underwent infertility treatment using ART. The group under study comprised 130 patients (the COC group) with the sperm selection via COC and subsequent ICSI procedure. The comparison group consisted of 137 patients, who underwent standard ICSI procedure with sperm selection according to morphological characteristics (the ICSI group). The clinical and embryological parameters of the ART program were assessed.

Results: The clinical results of the study showed that there was no significant increase in the frequency of implantation (38/5% in the COC group versus 35.9% in the ICSI group) in the general cohort of patients with sperm selection via COC. The frequency of successful delivery was similar (77.8% in the COC group versus 73.8% in the ICSI group). There were no significant improvements in the embryonic stage in the general cohort of patients. However, based on sperm morphology assessment, men with sperm morphology scores 0–1% and 2–3% were stratified into groups with mild and expressed teratozoospermia. The percentage of fertilization significantly increased (100% in the COC group and 77.78% in the ICSI group, p=0.001). The percentage of good and high quality growing blastocysts was also significantly higher in the group with sperm selection via COC (60% in the COC group versus 50% in the ICSI group, p=0.004).

Conclusion: The use of cumulus cells for sperm selection in ART programs for infertility treatment may improve the outcomes in patients with impaired spermatogenesis in the form of decreasing the percentage of morphologically normal spermatozoa in the ejaculate. In these married couples, fertilization rates can be improved, embryos can reach the blastocyst stage and higher number of embryos can be suitable for transfer to the uterus. This makes possible to reduce the cost of ovarian stimulation and to achieve pregnancy by frozen thawed embryo transfer in a cryo-cycle.