Clinical application of chromosomal karyotype analysis combined with chromosomal microarray analysis in the prenatal diagnosis of pregnant women with advanced maternal age

Background: This study aimed to investigate the clinical application value of chromosome karyotype analysis and union chromosome microarray analysis (CMA) in the prenatal diagnosis of pregnant women with advanced maternal age. Method: A total of 228 pregnant women who received invasive prenatal diagnosis due to advanced age in the Medical Genetics Department of Pingxiang Maternal and Child Health Hospital, Jiangxi Province, China from January 2021 to June 2022 were retrospectively analyzed. Results of chromosome karyotype analysis and CMA were compared. Results: (1) Chromosome karyotype analysis was performed in 228 elderly pregnant women, among which 213 were normal. Abnormal karyotype was found in 15 cases. (2) Among 228 elderly pregnant women, 211 had normal CMA results and 17 had abnormal CMA results. A total of 32 abnormal cases were detected by chromosome karyotype analysis combined with CMA. (3) A total of 15 cases had abnormal karyotype, only 6 cases had abnormal CMA results, and the coincidence rate of abnormal detection rate of the two methods was 40%.(4) Chromosome inversion, translocation, chimera, and polymorphism were not abnormal in CMA. Conclusion: The above two methods had advantages and disadvantages. Karyotype analysis and microarray analysis technology can effectively improve the detection rate of abnormalities in the prenatal diagnosis of older pregnant women. This finding suggested that clinicians should comprehensively analyze various influencing factors, conduct reasonable genetic counseling, and combine the two methods of analysis to improve the detection rate of fetal abnormalities and prevent birth defects in newborns.