Comprehensive molecular cytogenetic analysis of the human blastocyst stage
Authors: Fragouli, E.; Lenzi, M.; Ross, R.; Katz-Jaffe, M.; Schoolcraft, W.B.; Wells, D.
Source: Human Reproduction, Volume 23, Number 11, 6 November 2008 , pp. 2596-2608(13)
Publisher: Oxford University Press
Abstract:BACKGROUNDThe high frequency of chromosomal abnormalities observed in human gametes and embryos is unlike that seen in other mammalian species and is of great clinical significance, leading to high rates of pregnancy loss, and live-born children with aneuploid syndromes. Although much is known concerning the aneuploidy rates of oocytes, cleavage stage embryos and fetuses during pregnancy, the chromosomal status of blastocysts has been relatively little investigated.METHODSA total of 158 good quality blastocysts were examined using micromanipulation, whole genome amplification and comparative genomic hybridization.RESULTSFrom the obtained data, it was evident that the aneuploidy rate (38.8) is significantly lower for blastocysts than for embryos at earlier stages (51). However, in many cases, chromosome errors, including monosomy, imbalance affecting the larger chromosomes and complex aneuploidy persisted to this final stage of preimplantation development.CONCLUSIONSThis study represents the first attempt to gain a detailed insight into the extent and type of chromosome errors seen at the blastocyst stage, using a comprehensive molecular cytogenetic method. Our data suggest that the blastocyst stage does not represent an absolute selective barrier, and that the majority of aneuploid embryos are lost at the time of implantation or shortly thereafter.
Document Type: Research article
Publication date: 2008-11-06
- Human Reproduction features full-length, peer-reviewed papers reporting original research, clinical case histories, as well as opinions and debates on topical issues. Papers published cover the scientific and medical aspects of reproductive physiology and pathology, endocrinology, andrology, gonad function, gametogenesis, fertilization, embryo development, implantation, pregnancy, genetics, genetic diagnosis, oncology, infectious disease, surgery, contraception, infertility treatment, psychology, ethics and social issues. The highest scientific and editorial standard is maintained throughout the journal along with a rapid rate of publication.