Utilidad de la FISH en espermatozoides como análisis complementario de rutina en un laboratorio de andrología

Abstract

IntroductionFluorescent in situ hybridization (FISH) in decondensed sperm nuclei has proven to be a good method for determining the chromosome content of spermatozoa. Even among infertile men with a normal karyotype, there is a considerable frequency of chromosomal abnormalities limited to the germ line.In the present study, we have retrospectively analysed our FISH results on spermatozoa in a series of patients with normal karyotypes who have a risk of sperm chromosomal abnormalities due to several factors such as, recurrent spontaneous miscarriages, repeated implantation failures after ICSI and male factor. The objectives of the study were: a) to investigate whether these indications were actually associated with an increased incidence of sperm aneuploidy and diploidy; b) to examine the correlation between sperm chromosomal abnormalities on ICSI outcome in terms of fertilization, cleavage and embryo quality; and c) to find out if sperm FISH analysis could be used as a routine test in the andrology laboratory. Material and methodsSperm aneuploidy and diploidy rates for chromosomes 13, 14, 15, 18, 20, 21, 22, X and Y were evaluated in 158 patients with normal karyotypes using specific probes. Indications for sperm FISH analysis were: recurrent miscarriages of unknown aetiology (n=20), repeated implantation failures after ICSI (n=112) and male factor (n=26). We also retrospectively analysed ICSI outcome (fertilization rate, cleavage and embryo quality) before FISH analysis. ResultsThe incidence of sperm samples with a significant increase in aneuploidy was 26.5%. Oligoasthenoteratozoospermia patients: 30.7%, implantation failures: 21.4% and recurrent miscarriages: 50%. There was a total of 35.7% of patients with male factor and implantation failure with abnormal FISH results and 66.6% with male factor and recurrent miscarriages. There were no significant differences in fertilisation rate, cleavage and embryo quality between groups. ConclusionsOur results confirm a potential role for aneuploidy testing in the work-up of patients as a predictor of success, as well as in future genetic counselling.