Prenatal diagnosis value of chromosomal microarray in fetuses with thickened nuchal translucency

ObjectiveTo explore the prenatal diagnostic value of chromdsome microarray (CMA) in analyzing the thickening of nuchal translucency (NT) of fetus.

MethodsA total of 139 women with gestational 11-14 weeks whose fetuses were detected with increased NT (NT≥2.5 mm) were selected.They were divided into four groups with NT value of 1 mm as an interval, including 2.5-3.4 mm, 3.5-4.4 mm, 4.5-5.4 mm, and ≥5.5 mm groups.Fetal specimens were performed for karyotype analysis and copy number variants (CNV) sequencing.

ResultsWith the increase in NT thickness, the live birth rate tended to decrease (P < 0.01) and the corresponding abnormal CNV detection rate tended to increase (P < 0.01).Among the 139 cases, 35 cases (25.2%) had abnormal karyotype, 45 cases (32.3%) had abnormal CNV.Among the 12 cases with abnormal CNV and normal karyotype, 2 cases were pathogenic CNV, 7 cases were CNV of unknown clinical significance, and 3 cases were possibly benign CNV.There was no statistically significant difference in CNV abnormalities between elderly and non-elderly pregnant women (P>0.05).The rate of abnormal CNV in NT alone was lower than that of NT combined with other ultrasound (P < 0.05), and the rate of abnormal CNV was lower than that of induced labor in those with live births (P < 0.01).

ConclusionsNT thickened fetuses should be combined with CMA karyotype analysis to provide the basis for genetic counseling, which is of great significance for prenatal diagnosis.