title: Embryos with morphokinetic abnormalities may develop into euploid blastocysts.
abstract: Irregular cleavage divisions are expected to produce chromosomally deviant embryos. We investigated whether embryos from irregular cleavages could develop into euploid blastocysts, and, if so, whether any evidence existed of a self-correction mechanism of the embryo. We also investigated the role of different dynamic aspects of morula compaction in this process. A total of 791 embryos from 141 patients undergoing pre-implantation genetic screening were retrospectively analysed using a time-lapse imaging system, and multiple cell divisions were evaluated. A total of 276 embryos developed into blastocysts suitable for biopsy and chromosome screening through array-comparative genomic hybridization. As well as testing trophectoderm biopsy specimens for aneuploidy, excluded cells of 18 blastocysts, which developed from partially compacted morulas, were also analysed. Unique data on the developmental fate of embryos with cleavage abnormalities are presented, and a potential mechanism of 'aneuploidy rescue' is postulated through which mosaic embryos may form partially compacted morulas to exclude aneuploid cells. In addition, this process seems to be less efficient in older women. The data obtained also provide further evidence that excluded cells should not be used to infer the cytogenetic status of the embryo.
authors.affiliation: 9.Baby Center for Reproductive Health, via Dante, 15-40125 Bologna, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Lagalla
authors.affiliation: 9.Baby Center for Reproductive Health, via Dante, 15-40125 Bologna, Italy.
authors.forename: N
authors.initials: N
authors.lastname: Tarozzi
authors.affiliation: 9.Baby Center for Reproductive Health, via Dante, 15-40125 Bologna, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Sciajno
authors.affiliation: Reprogenetics UK, Institute of Reproductive Sciences, Business Park North, OX4 2HW Oxford, UK; Nuffield Department of Obstetrics and Gynaecology, University of Oxford, OX3 9DU Oxford, UK.
authors.forename: D
authors.initials: D
authors.lastname: Wells
authors.affiliation: 9.Baby Center for Reproductive Health, via Dante, 15-40125 Bologna, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Di Santo
authors.affiliation: 9.Baby Center for Reproductive Health, via Dante, 15-40125 Bologna, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Nadalini
authors.affiliation: 9.Baby Center for Reproductive Health, via Dante, 15-40125 Bologna, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Distratis
authors.affiliation: 9.Baby Center for Reproductive Health, via Dante, 15-40125 Bologna, Italy. Electronic address: borini@tecnobiosprocreazione.it.
authors.forename: A
authors.initials: A
authors.lastname: Borini
mesh_terms: D000328:Adult; D000782:Aneuploidy; D001706:Biopsy; D001755:Blastocyst / Q000166:cytology*; D002970:Cleavage Stage, Ovum; D055028:Comparative Genomic Hybridization; D003582:Cytogenetics; D010064:Embryo Implantation; D047108:Embryonic Development; D005260:Female; D006801:Humans; D008875:Middle Aged; D009028:Morula / Q000378:metabolism; D011003:Ploidies; D011247:Pregnancy; D019836:Preimplantation Diagnosis / Q000379:methods*; D012189:Retrospective Studies
keywords: aneuploidy rescue; arrayCGH; irregular cell divisions; morphokinetics; morula compaction; pre-implantation genetic screening; time-lapse