Analysis of POC specimens by karyotyping fails in 20-40% of cases. SNP-based CMA is a robust platform, with successful results obtained in >90% of cases. SNP-based CMA can identify aneuploidy, polyploidy, whole-genome homozygosity, segmental genomic imbalances, and maternal cell contamination, thus maximizing sensitivity and decreasing false-negative results. Understanding the etiology of fetal loss enables clarification of recurrence risk and assists in determining appropriate management for future family planning.Genet Med 19 1, 83-89.

What's already known about this topic? Current professional guidelines regarding the use of chromosomal microarray analysis (CMA) versus karyotyping in prenatal diagnosis support CMA over karyotype only when fetal structural abnormalities are present.Examination of the clinical utility of these guidelines, given advances in microarray technology and prenatal screening, is largely unaddressed. What does this study add? This study demonstrates the diagnostic superiority of CMA by SNP microarray compared with karyotyping for prenatal diagnosis, regardless of the clinical indication for testing.

(Abstracted from Genet Med 2017;19(1):83–89) High-resolution chromosomal microarray analysis (CMA) with single-nucleotide polymorphism (SNP)–based arrays is increasingly used for pediatric and prenatal diagnoses as they can simultaneously detect aneuploidies, submicroscopic chromosomal imbalances, triploidy, and regions of allelic homozygosity. Overall, 15% to 20% of clinically recognized pregnancies end in miscarriage, and approximately 1% of couples experience recurrent (at least 2) pregnancy losses.