Fluorescent in situ hybridization of human sperm: diagnostics, indications, and therapeutic implications

Male factor infertility is a relatively common condition, affecting at least 6% of men of reproductive age. Typically, men with unknown genetic abnormalities resort to using assisted reproductive techniques (ART) to achieve their reproductive goals. Infertile men who father biological children using ART could have a higher incidence of aneuploidy, which is a deviation from the normal haploid or diploid chromosomal state. Aneuploidy can be evaluated using fluorescent in situ hybridization (FISH), a cytogenetic assay that gives an estimate of the frequencies of chromosomal abnormalities. The chromosomes that are generally analyzed in FISH (13, 18, 21, X, and Y) are associated with aneuploidies that are compatible with life. The technique is indicated for various reasons but primarily in [1] men who despite normal semen parameters suffer recurrent pregnancy loss, and [2] men with normal semen parameters, who are undergoing in vitro fertilization but still experiencing recurrent implantation failure. As a screening tool, the technique can help in reproductive and genetic counseling of affected couples, or those who have previously experienced failure of ART. A qualitative analysis of FISH study results allows couples to make informed reproductive choices. Given the increasing clinical use of FISH in various infertility diagnoses, and the development of novel adjunct technologies, one can expect much progress in the areas of preimplantation genetic screening, diagnostics, and therapeutics.