Analysis of chromosomal abnormalities in human spermatozoa using multi-colour fluorescence in-situ hybridization

There is concern that intracytoplasmic sperm injection (ICSI) may lead to offspring with a high frequency of chromosomal abnormalities. Accordingly, we studied spermatozoa sampled from eight infertile men with oligoasthenoteratozoospermia (OAT) by multi-colour fluorescence in-situ hybridization (FISH), using DNA probes for chromosomes 13, 18, 21, X and Y. Results were compared with those of spermatozoa sampled from 10 healthy men with normal semen profiles. Analysis of the diploidy values was repeated twice in each of the 18 men. There was no significant difference in the two diploidy estimates; thus the FISH technique appeared to be accurate and reliable for determining aneuploidy in human spermatozoa. We found the average frequencies of disomy for chromosomes 13, 18, 21 and X or Y to be 0.13, 0.12, 0.24 and 0.59% respectively for the OAT group and 0.09, 0.13, 0.19 and 0.38% respectively for the control group. The diploidy rate was 0.29% in the OAT group, and 0.16% in the control group. Thus, the OAT group showed a significantly higher frequency of disomy for chromosomes 13 (P < 0.001), 21 (P < 0.05), sex (P < 0.001), and diploidy (P < 0.005) than the control group. This finding suggests there may be some risk of aneuploidy in the offspring conceived by the ICSI technique.