Different oocyte fertilization methods and their relationship to the effectiveness of assisted reproductive technology programs in the treatment of infertility

Objective. To determine the relationship between the type of oocyte fertilization, embryological parameters (oocyte fertilization rate; blastulation rate), and clinical outcomes in assisted reproductive technology (ART) programs using different fertilization procedures (vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and physiological intracytoplasmic sperm injection (PICSI). Subjects and methods. A prospective case-control study covered 196 married couples undergoing the program of IVF, IVF/ICSI), IVF/PICSI. The couples were divided into 3groups according to the type of fertilization: 1) 32 couples who underwent IVF; 2) 105 couples who had ICSI; 3) 59 couples who had PICSI. The embryological parameters (oocyte fertilization rate; blastulation rate) and clinical outcomes in the ART programs were assessed. Results. Our investigation conducted in the compared groups showed a statistically significant association between the type of oocyte fertilization and the rate of implantation. There were significant differences in implantation rates between Groups 1 and 2 (χ2 = 6.0; P = 0.014). The implantation rates were 40.5% in Group 1, 33.1% in Group 2, and 50% in Group 2). A statistically significant difference was also found in clinical pregnancy rates. In the PICSI group where spermatozoa were selected for their hyaluronic acid (HA)-binding ability before ICSI), the clinical pregnancy rate was higher and equal to 59.3% (in 35patients; it was 40.6% (in 13 married couples) in Group 1 (conventional IVF) and 38.1% (in 40 patients) in Group 2. There were statistically significant differences between the rate of oocyte fertilization and that of blastulation. However, the rate of non-developing pregnancy in Group 1 (conventional IVF) was 7.7% while in the ICSI and PICSI groups it was 31 and 11%, respectively, which confirms the fundamental role of physiological sperm selection during conventional fertilization (IVF) and in the use of HA as a selector of gametes (PICSI). Significant differences in live birth rates per pregnancies after ART programs were also identified in favor of Group 1 (conventional IVF) and Group 3 (physiological selection of male gametes for ICSI) as compared with Group 2 (ICSI). Furthermore, the groups compared showed a statistically significant difference in live birth rates per embryo transfer into the uterus. In Group 1 (conventional IVF), the live birth rate was 36.4% calculated per embryo, whereas it was 27.6% in Group II (IVF/ICSI) and 53.30% in Group 3 (selection of spermatozoa for their HA-binding ability). Conclusion. The data collected for today confirm the prospects of studying the significance of various modern methods of male reproductive cells selection for the purpose of differential approach to the treatment of married couples. Studies demonstrate encouraging results that can be applied in clinical practice not only to optimize the choice of the fertilization technique, but also to expand the scope of the examination before the IVF program.

in vitro fertilization, infertility, hyaluronic acid, sperm selection, intracytoplasmic sperm injection, physiological intracytoplasmic sperm injection, assisted reproductive technologies