ABSTRACT
BACKGROUND: The biopsy of both polar bodies and a blastomere from the same embryo was investigated as an approach aimed at increasing the quantity of DNA available for genetic analysis in preimplantation embryos. METHODS: In 113 cycles, preimplantation genetic diagnosis (PGD) was performed for aneuploidy: 19 cycles underwent polar body biopsy, 32 cycles had both polar body and blastomere biopsy done, and the remaining 62 cycles underwent blastomere biopsy. The chromosomal analysis was performed in a two-round fluorescence in situ hybridization (FISH) protocol with probes specific for the chromosomes X, Y, 13, 15, 16, 18, 21 and 22. RESULTS: The morphological evaluation of the analysed embryos demonstrated similar rates of development irrespective of the biopsy procedure. Accordingly, the implantation rate did not differ significantly in the three biopsy groups and was 15% after polar body biopsy, 26% after the combined biopsy procedures of polar bodies and blastomeres, and 25% after blastomere biopsy. CONCLUSIONS: The removal of a blastomere subsequent to polar body biopsy does not seem to have negative effects on embryo viability. This approach could be especially valuable for a combined diagnosis of aneuploidy and single-gene disorders in preimplantation embryos generated by couples at high reproductive risk.
