Application of Chromosomal Microarray Analysis in Prenatal Diagnosis of Fetuses with Increased Nuhal Translucency

LIANG Yi-xuan; ZHOU Ran; MENG Lu-lu; LIU Ting-ting; HUO Hai-qin; ZHANG Qin-xin; HU Ping; XU Zheng-feng; WANG Yan

doi:10.12280/gjfckx.20250061

Abstract：Objective:To investigate the application value of chromosomal microarray analysis(CMA)in the prenatal diagnosis of fetuses with increased nuchal translucency(NT).Methods:A total of 1 033 pregnant women with increased NT(≥3.0 mum)detected by ultrasound and who underwent CMA testing at the Women's Hospital of Nanjing Medical University from June 2017 to June 2024 were selected.According to the presence of other ultrasonographic soft markers,they were divided into a simple increased NT group(918 cases)and increased NT combined with other ultrasonographic soft markers group(115 cases).The simple increased NT group was further divided into an advanced-age group(≥35 years old,135 cases)and a non-advanced-age group(＜35 years old,783 cases)according to the pregnant women's age;and divided into a 3.0-3.4 mm group(506 cases),a 3.5-4.4 mm group(288 cases),a 4.5-5.4 mm group(80 cases)and a ≥5.5 mm group(44 cases)according to the NT thickness.Results:Among the 1 033 fetuses with increased NT,170 cases(16.5％)of chromosomal abnormalities were detected,including 122 cases(11.8％)of chromosomal aneuploidy,10 cases(1.0％)of large-scale structural abnormalities[(copy number variations,CNV)≥10 Mb]and 38 cases(3.7％)of pathogenic microdeletion and microduplication(CNV＜10 Mb).The detection rate of chromosomal abnormalities in the increased NT combined with other ultrasonographic soft markers group was significantly higher than in the simple increased NT group(39.1％vs.13.6％,x2=48.388,P＜0.001).In the simple increased NT group,the detection rate of chromosomal abnormalities in the advanced-age group was significantly higher than that in the non-advanced-age group(25.9％vs.11.5％,x2=20.389,P＜0.001).In both the advanced-age and non-advanced-age group,the detection rate of chromosomal abnormalities significantly increased with the increased NT thickness(all P＜0.05).When NT values were between 3.5-4.4 mm and 4.5-5.4 mm,the detection rate of chromosomal abnormalities in the advanced-age group was significantly higher than that in the non-advanced-age group(45.0％vs.10.9％,P＜0.001;42.9％vs.16.7％,P=0.040).Conclusions:In addition to aneuploidy,chromosomal microdeletion and microduplication are closely related to increased NT.CMA can effectively improve the detection rate of chromosomal abnormalities in fetuses with increased NT.The detection rate of chromosomal abnormalities shows an upward trend with the increase of NT thickness.Increased NT combined with advanced maternal age or other ultrasonographic soft markers will increase the risk of fetal chromosomal abnormalities.