Clinical Application of Chromosomal Microarray Analysis in High-Risk Pregnancies

Abstract Objective To evaluate the value of chromosomal microarray analysis (CMA) in the prenatal diagnosis of high-risk pregnancies.Methods A total of 3459 pregnant women admitted to the Wuxi Maternal and Child Health Hospital between June 2020 and August 2022 were selected for this study. Both G-banding karyotype analysis and CMA were offered to all patients who underwent invasive prenatal diagnosis. Short tandem repeat (STR) analysis was performed to eliminate maternal contamination for interpretation.Results Chromosomal aberrations, including aneuploidies or triploid and mosaic aberrant karyotypes and copy number variants (CNVs) ≥ 5Mb, were detected by both G-banding karyotyping and CMA in 174 (5.0%) cases. A total of 326 (9.4%) cases with normal karyotypes were reported as CNVs in CMA, including 71 (2.1%) cases with pathogenic and likely pathogenic CNVs and 217(6.3%) cases with variants of uncertain significance (VOUS). On the other hand, 11 inversions, 23 balanced translocations, and 22 other chromosomal rearrangements were detected by karyotyping with normal CMA results.Conclusion The top 3 detection rates of different indications by CMA or karyotyping were 43.5% for NIPT high risk, 17.5% for abnormal ultrasound, and 17.7% for other indications. CMA is an effective diagnostic tool for high-risk pregnancies in perinatal medicine.