Triploidy that escaped diagnosis using chromosomal microarray testing in early pregnancy loss: Two cases and a literature review

Abstract

About 15% to 20% of all clinically recognized pregnancies result in spontaneous abortion or miscarriage, and chromosomalanomalies can be identified in up to 50% of first trimester miscarriages. Chromosomal microarray analysis (CMA) is currentlyconsidered first-tier testing for detecting fetal chromosomal abnormalities and is supported by the absence of cell culture failure or erroneous results due to cell contamination in pregnancy loss. Triploidy is a lethal chromosome number abnormalitycharacterized by an extra haploid set of chromosomes. Triploidy is one of the most common chromosomal aberrations in firsttrimester spontaneous abortions. Here, we report two cases of triploidy abortion that were not detected using array comparative genomic hybridization-based CMA. The aim of this report was to remind clinicians of the limitations of chromosomaltesting and the misdiagnosis that can result from biased test selection.