Higher chromosomal abnormality rate in blastocysts from young patients with idiopathic recurrent pregnancy loss

Abstract

To determine whether the incidence of chromosomal abnormalities in blastocysts is higher in patients with idiopathic recurrent pregnancy loss (iRPL) who underwent preimplantation genetic testing for aneuploidy (PGT-A) than in those who underwent preimplantation genetic testing for monogenic defects (PGT-M). Retrospective cohort study. University-affiliated reproductive center. A total of 62 patients with iRPL underwent 101 PGT-A cycles (iRPL group), and 212 patients underwent 311 PGT-M cycles (control group). Blastocyst biopsy and comprehensive chromosome screening technologies, including single-nucleotide polymorphism microarrays and next-generation sequencing. Incidence of chromosomal abnormalities in blastocysts and clinical miscarriage (CM) rate. Stratification analysis by maternal age showed an increased incidence of chromosomal abnormalities in the iRPL group aged ≤35 years (48.9% vs. 36.9%), whereas no significant increase was found in the iRPL group aged >35 years (66.9% vs. 61.4%). After transfer of euploid embryos, women aged ≤35 years with iRPL exhibited an increased CM rate compared with the control group (26.1% vs. 3.1%). Young patients with iRPL have a significantly higher rate of chromosomal abnormalities in blastocysts compared with patients with no or sporadic CM. Although euploid embryos were transferred after PGT-A, young patients with iRPL had a higher CM rate, which may indicate that chromosomal abnormalities might not be the only causal factor for iRPL. Therefore, the role of PGT-A in iRPL still needs to be clarified.