囊胚期胚胎之blastocoel fluid 無法代表ICM 或TE之實際karyotyping狀況, 相符率僅40%

ICM 或TE之實際karyotyping狀況, 相符率85%

Fertil Steril. 2018 Jun;109(6):1127-1134.e1. doi: 10.1016/j.fertnstert.2018.02.008.

Karyotype of the blastocoel fluid demonstrates low concordance with both trophectoderm and inner cell mass.

Tšuiko O1, Zhigalina DI2, Jatsenko T3, Skryabin NA4, Kanbekova OR5, Artyukhova VG6, Svetlakov AV6, Teearu K7, Trošin A8, Salumets A9, Kurg A7, Lebedev IN10.

Author information

Abstract

OBJECTIVE:

To compare the genomic profiles of blastocoel fluid (BF), inner cell mass (ICM), and trophectoderm (TE) cells derived from the same blastocyst.

DESIGN:

Prospective study.

SETTING:

Academic and in vitro fertilization units.

PATIENT(S):

Sixteen donated cryopreserved embryos at blastocyst stage.

INTERVENTION(S):

BF, TE, and ICM cells were retrieved from each blastocyst for chromosome analysis by means of next-generation sequencing (NGS).

MAIN OUTCOME MEASURE(S):

Aneuploidy screening and assessment of mosaicism in BF, TE and ICM samples with subsequent comparison of genomic profiles between the three blastocyst compartments.

RESULT(S):

Out of 16 blastocysts, 10 BF samples and 14 TE and ICM samples provided reliable NGS data for comprehensive chromosome analysis. Only 40.0% of BF-DNA karyotypes were fully concordant with TE or ICM, compared with 85.7% concordance between TE and ICM. In addition, BF-DNA was burdened with mosaic aneuploidies and the total number of affected chromosomes in BF was significantly higher compared with the TE and ICM.

CONCLUSION(S):

BF-DNA can be successfully amplified and subjected to NGS, but owing to increased discordance with ICM and TE, BF does not adequately represent the status of the rest of the embryo. To overcome biologic and technical challenges associated with BF sampling and processing, blastocentesis would require improvement in both laboratory protocols and aneuploidy calling algorithms. Therefore, TE biopsy remains the most effective way to predict embryonic karyotype, and the use of BF as a single source of DNA for preimplantation genetic screening is not yet advised.