The value of combined use of chromosomal karyotyping and chromosome microarray analysis for prenatal diagnosis

OBJECTIVE: To assess the value of combined chromosomal karyotyping and chromosomal microarray analysis (CMA) for prenatal diagnosis. METHODS: G-banding karyotyping and CMA were simultaneously performed on 546 women who were subjected to amniocentesis during middle pregnancy. RESULTS: In total 82 cases were detected with chromosomal abnormalities. The two methods were consistent in 43 cases, which included 14 trisomy 21, 6 trisomy 18, 1 trisomy 13, 14 sex chromosomal aneuploidies, 4 chromosomal deletions, 3 chromosomal duplications and 1 sex chromosomal mosaicism. Fifteen fetuses with chromosomal abnormalities detected by CMA were missed by karyotyping analysis, which included 9 microdeletions and 6 microduplications. Sixteen fetuses with chromosomal abnormalities detected by karyotyping analysis were missed by CMA, which included 15 chromosomal translocations and 1 sex chromosomal mosaicism. In 7 cases, the results of karyotyping analysis and CMA were inconsistent. One supernumerary marker chromosome detected by karyotyping analysis was verified by CMA as 9p13.1p21.1 duplication. CONCLUSION: Combined chromosomal karyotyping and CMA can significantly improve the detection rate for chromosomal abnormalities, which has a great value for prenatal diagnosis.