Sperm morphological abnormalities visualised at high magnification predict embryonic development, from fertilisation to the blastocyst stage, in couples undergoing ICSI.

Abstract

To investigate the predictive value of the motile sperm organelle morphology examination (MSOME) on embryo morphology. The morphologies of 540 embryos obtained from 60 couples undergoing ICSI were evaluated from days 1 to 5 of development and were examined for associations with the percentages of morphologically normal paternal sperm and of the paternal sperm with large nuclear vacuoles (LNVs) as determined by MSOME. An increased percentage of LNV sperm was associated with increased odds of a zygote presenting with pronuclear abnormalities. It was also associated with decreased odds of (i) normal cleavage on days 2 and 3 of development, (ii) the presence of a high-quality embryo on day 3, (iii) the development of an embryo to the blastocyst stage, and (iv) an embryo possessing a normal trophectoderm and inner cell mass. The calculated areas under the curves differed for the embryos that did and did not develop to the blastocyst stage and for the high- and low-quality blastocysts. The optimal cut-off value for the percentage of LNV sperm that maximised proper blastocyst formation was ≤24.5 %, and the cut-off value that maximised blastocyst quality was ≤19.5 %. These results suggest a very early onset of paternal influences on embryo development. The evaluation of the incidence of vacuoles by MSOME may significantly improve upon the prognostic information provided by conventional semen analyses.