Chromosomal analysis for embryos from balanced chromosomal rearrangement carriers using next generation sequencing.

ABSTRACT

We aimed to use next generation sequencing (NGS) to investigate chromosomal abnormalities in blastocyst trophectoderm (TE) samples, and reproductive outcomes with the different types of chromosomal rearrangements (CR) and for each sex of CR carrier. A total of 1189 blastocyst TE samples were evaluated using NGS to detect chromosomal unbalanced translocations as well as aneuploidy, including blastocytes from 637 blastocysts from carriers of balanced CR and 552 blastocysts from carriers of normal chromosomes. The optimal embryos had lower chromosomal abnormality rates compared to the poor-quality embryos. The experimental group had significantly reduced rates of normal embryos and euploidy, and higher rates of total abnormalities, aneuploidy and unbalanced chromosomal aberrations. Carriers of reciprocal translocations had a reduced rate of normal embryos and an increased percentage of embryos with total abnormalities and unbalanced chromosomal aberrations compared with carriers of Robertsonian translocations. Couples with female carriers of chromosomal abnormalities had significantly reduced rates of normal embryos and euploidy, and a higher percentage of embryos with total abnormalities, aneuploidy, and unbalanced chromosomal aberrations compared with couples of male carriers. Our preimplantation genetic testing (PGT) study identified higher rates of chromosomal abnormalities, including chromosomal unbalanced translocations and aneuploidy, in blastocysts from CR carriers, especially from the female carriers, in a Chinese population. The PGT cycles successfully improved clinical outcomes by increasing the fertilization rate and reducing the early spontaneous abortion rate compared with the in vitro fertilization and intracytoplasmic sperm injection cycles, especially for CR carriers.