Abstract:

Objective The study tried to explore the value of combined karyotype analysis and chromo⁃ some microarray analysis（CMA）in clinical application of prenatal diagnosis. Methods A total of 4 854 pregnant women underwent invasive prenatal diagnosis for different indications in the Prenatal Diagnosis Center of Jiangxi Maternal and Child Health Hospital from January 2020 to December 2021，and the test results of karyotype analysis and CMA were analyzed retrospectively. Results A total of 848 cases with chromosomal abnormalities were detected in 4 854 prenatal fetal samples，and the abnormal detection rate was 17.47%. 540 cases of them were detected with pathogenic chromosomal abnormalities，with a detection rate of 11.12%. 151 cases with pathogenic copy number variations（CNVs）and likely pathogenic CNVs were detected by CMA，while 108 cases of these had normal karyotypes. Therefore，a detection rate of 2.22% increased by CMA for fetal pathogenic chromosomal abnor⁃ mality compared with traditional karyotype analysis. 75 cases with balanced translocation were detected by karyo⁃ type analysis but showed no obvious abnormality by CMA. Furthermore，9 cases were detected with inconsistent results by karyotype analysis and CMA. Conclusions Combined CMA and traditional karyotype analysis improved the detection rate of fetal chromosomal abnormalities and they complemented each other，which would provide more detailed and accurate information for prenatal diagnosis and genetic counseling as well as a more objective basis of continue pregnancy for these pregnant women.

Key words:

chromosome abnormality, chromosome microarray analysis, prenatal diagnosis, small supernumerary marker chromosome