High incidence of complex chromosome abnormality in cleavage embryos from patients with repeated implantation failure

Objective: To analyze the chromosome abnormalities observed in the course of preimplantation aneuploidy screening using comparative genomic hybridization (CGH) on single blastomeres in relation to maternal age and previous IVF history. Design; Retrospective analytical study. Setting: A large IVF unit and the research laboratory of an associated clinical genetics unit. Patient(s): Twenty-eight women referred for aneuploidy screening of cleavage embryos. Intervention(s): Blastomere biopsy. Main Outcome Measure(s): The incidence of aneuploidy and complex abnormality in human cleavage embryos. Result(s): The incidence in embryos of aneuploidy for one to two chromosomes was significantly increased with advanced maternal age, but was independent of any history of recurrent implantation failure. In comparison, the incidence of complex chromosome abnormality (which involves three or more chromosomes) was independent of maternal age but significantly increased in embryos from patients with a history of recurrent implantation failure. Conclusion(s): The incidence of complex abnormality in healthy cleavage embryos is independent of maternal age but is increased in patients with a history of recurrent implantation failure. These results suggest that the pathology underlying complex abnormality is different from that resulting in aneuploidy of one to two chromosomes but particularly relevant to women with recurrent implantation failure.