Purpose: To evaluate whether the morphologically normal spermatozoa selected for intracytoplasmic sperm injection (ICSI) under microscope had a higher rate of normal/balanced chromosome contents than that in the whole unselected sperm from reciprocal translocation carriers.
Methods: Five hundred unselected spermatozoa from each of 40 male translocation carriers were performed with fluorescence in situ hybridization (FISH), to determine the rates of gametes with different meiotic contents of translocated chromosomes. Meanwhile, 3030 biopsied blastocysts from 239 male and 293 female reciprocal translocation carriers were detected with the microarray technique to analyze the rates of embryos with different translocated chromosome contents.
Results: The D3 embryo rate, blastocyst formation rate, and euploid rate of blastocysts were remarkably higher in male carriers than those in female (p = 0.001, p = 0.004, and p = 0.035, respectively). In addition, the percentages of alternate products, which contained normal/balanced chromosome contents, in embryos from male carriers were markedly higher than those in sperm FISH (p = 2.48 × 10-5 and p = 2.88 × 10-10), while the percentages of adjacent-2 and 3:1 products were lower than those in sperm FISH (p = 0.003 and p = 5.28 × 10-44). Moreover, consistent results were obtained when comparing the rates of products in embryos between male and female carriers. Specifically, the incidence of alternate products in male carriers was higher than those in female carriers (p = 0.022). However, no similar differences were seen between sperm and embryos of female carriers.
Conclusion: ICSI facilitates the selection of spermatozoa with normal/balanced chromosome contents and improves the D3 embryo rate, blastocyst formation rate, and the euploid embryo rate in male carriers.
Keywords: Alternate products; ICSI; Male reciprocal translocation; Quadrivalent structure; Segregation patterns; Sperm FISH.