Use of a sperm FcR assay in intracytoplasmic sperm injection improves day 5 good quality blastocyst yield

The Kinetix FcR binding assay results correlate to male fertility in intrauterine insemination. Kinetix measures temporal expression of a sperm Fc receptor as sperm capacitate and become fertile, which in healthy ejaculates occurs over time in sequential groups. We evaluated the ability of Kinetix to predict ICSI outcomes.

A prospective observational study was conducted on human semen samples during ICSI procedures to measure the changing proportion of sperm expressing the FcR over time. Semen samples were then categorized as "Fertile," "Subfertile," or "Infertile" depending on the pattern of functional sperm populations. The fertilization rate, yield of day 5 total, and day 5 good quality blastocysts (GQB) were quantitated.

We found 2.9 times more day 5 GQB/2PN (2 pronuclei (2PN) visible) using sperm identified as Fertile compared to the Infertile group. No day 5 GQB were produced in 65% of cycles using sperm from the Infertile group. Day 5 GQB were produced in 65% of cycles using sperm from the Subfertile and 77% from the Fertile group of ejaculates. Male and female demographics, rapidly progressive motility, and sperm concentration were not statistically different across groups.

Notably, the sperm functional characteristics revealed by the Kinetix Sperm FcR Assay were irrespective of semen quality as defined by current semen analysis techniques. It is likely that a higher Kinetix score reflects the presence and ultimate injection of higher quality sperm, which improves the yield of day 5 good quality blastocysts.