Single‐blind clinical trial: Sperm selection based on capacity to pass through cumulus oophorous column improves ICSI outcomes

Abstract

Background: Sperm selection procedures for future strategies that aim to select normal spermatozoa with intact DNA to improve intracytoplasmic sperm injection (ICSI) outcomes are in early developing stage. Objectives:The objective is to find out whether the sperm selection procedure based on the ability of spermatozoa to traverse the cumulus cells could improve clinical outcomes of ICSI technique in infertile couples with male factor etiology. Materials and methods:For this single-blind clinical trial, mature metaphase II oocytes were retrieved from 150 couples with male factor infertility, male age lower than 45 years and female age under 38 years. These couples were divided into two groups.In control group (n = 75), spermatozoa processed by density gradient centrifugation (DGC) were used to inject the oocytes. In the study group (n = 75), the oocytes were divided into sibling groups. In one sibling group (DGC), the oocytes were inseminated with DGC-processed spermatozoa while in the other group (DGC-CC), they were inseminated with DGC-processed spermatozoa that passed cumulus oophorous column.Results: Mean fertilization and embryo quality were significantly higher in DGC-CC group compared to DGC and control group. In addition, mean of chemical pregnancy (52.27% vs. 34.14%; p = 0.05), clinical pregnancy based on sac (52.27% vs. 32.92%; p = 0.03), clinical pregnancy with heart beat (52.27% vs. 25.60%; p = 0.003) and ongoing pregnancy (43.18% vs. 21.95%; p = 0.02) rates were significantly higher in DGC-CC group compared to control group. Conclusion:Sperm selection based on integrated systems such as DGC and ability to pass through cumulus oophorous column could improve clinical outcomes of ICSI in couples with male factor infertility.

Sperm selection by the oviduct: perspectives for male fertility and assisted reproductive technologies

“…Furthermore, a system consisting of a column filled with cumulus cells has been developed to select human sperm for IVF/ICSI. Sperm that go through the column show higher rates of normal morphology and good motility parameters, compared with sperm that do not pass the column [156], and induce higher fertilization and pregnancy rates after ICSI, compared with conventional sperm selection with a density gradient [157]. A similar study, which tested the ability of sperm to go through a group of COCs in a microfluidic device, found not only better motility parameters, but also lower DNA fragmentation compared with sperm that did not traverse the COCs [158].…”

Only the Best of the Bunch—Sperm Preparation Is Not Just about Numbers

“…This knowledge underpins the principle of sperm preparation and selection-for example, there are sperm within the population that are desired above othersbut also suggests that sperms undergo physiological selection steps that are not just chance and instead require certain characteristics. Whether this means that fewer good sperms should be prepared out of a population through a physiological step such as viscosity, 67 cumulus penetration, 68,69 or other challenges remains to be seen.…”