Nuclei size in relation to nuclear status and aneuploidy rate for 13 chromosomes in donated four cells embryos.

Purpose: The aim was to elucidate if the nuclear size and number are indicative of aberrant chromosome content in human blastomeres and embryos.

Methods: The number of nuclei and the nucleus and blastomere size were measured by a computer controlled system for multilevel analysis. Then the nuclei were enumerated for 13 chromosomes by a combination of PNA and DNA probes.

Results: In the mononucleated embryos there was no difference in the mean size of chromosomally normal and abnormal nuclei but a significant difference in the mean nuclei size of nuclei that had gained chromosomes compared to nuclei that had lost chromosomes. The nuclei from multinucleated blastomeres had a significant smaller mean size and the frequency of chromosomally aberrant blastomeres was significantly higher.

Conclusion: The mean nuclear size is not a marker for the chromosome content in mononucleated embryos. However, it seems that the nuclei size can be related to multinucleation and maybe to the chromosome content.