Chromosomal analysis of blastocyst derived from monopronucleated ICSI zygotes: approach by double trophectoderm biopsy

Abstract

ObjectiveThis study aims to increase the knowledge about monopronucleated ICSI-derived blastocysts, analyzing trophectoderm biopsies by aCGH and FISH to evaluate their chromosome constitution.MethodsFifteen monopronucleated ICSI-derived blastocysts were studied. Double trophectoderm biopsy was performed and analyzed by FISH and aCGH. The blastocysts were classified according to chromosome constitution. Disagreements between the two techniques were assessed.ResultsResults obtained after FISH and aCGH analyses showed the following: 20% (3/15) and 60% (9/15) diploid females, respectively; 26.7% (4/15) and 26.7% (4/15) diploid males, respectively; and 53.3% (8/15) and 13.3% (2/15) mosaics, respectively. No mosaic male embryos were found using FISH or aCGH. There were disagreements in 40% (6/15) of the cases due to the higher detection of mosaicism by FISH compared to aCGH.ConclusionsThe combination of FISH and aCGH has been shown to be a suitable approach to increase the knowledge about monopronucleated ICSI-derived embryos. FISH analysis of blastocysts derived from monopronucleated ICSI zygotes enabled us to conclude that aCGH underestimates haploidy. Some diploid embryos diagnosed by aCGH are in fact mosaic. In cases where these embryos would be used for reproductive purposes, extra analysis of parental genome origin is recommended.

Do serum androgens influence blastocysts ploidy in karyotypically normal women?

“…Additionally, all IVF cycles and PGT were performed in a single center. This seems to be an important factor as having different laboratories that use various methods of aneuploidy screening could affect the results (Mateo et al 2017;Munné et al 2017;Grati et al 2018;Spinella et al 2018).…”

Genome-wide haplotyping embryos developing from 0PN and 1PN zygotes increases transferrable embryos in PGT-M

“…Similarly to 0PNs, successful development to term has been reported following transfers of 1PN-derived embryos ( Staessen et al , 1993 ; Dasig et al , 2004 ; Itoi et al , 2015 ; Bradley et al , 2017 ; Mateo et al , 2017b ) and previous cytogenetic analyses report the detection of 1PN diploid embryos albeit with high variabilty (2.2–80.5%, reviewed in Rosenbusch (2014 )). Several groups have thus advocated that a considerable loss of zygotes can be overcome by implementing a genetic analysis technology to confirm bi-parental diploidy in the embryos developing from 0PN and 1PN zygotes ( Levron et al , 1995 ; Li et al , 2015 ; Bradley et al , 2017 ; Capalbo et al , 2017 ; Mateo et al , 2017a , b ).…”