Ultrasonic Diagnosis Of Fetal Aortic Arch Anomalies And Its Clinical Study On 22q11 Microdeletion

Objective: To conclude the ultrasonographic characteristics of three vessels trachea view,subclavian artery view and coronal view of the descending aortic arch for the fetus with aortic arch anomalies (AAA) and evaluate its value in the diagnosis of fetal aortic arch anomalies.And to discuss the clinical application value of chromosome microarray analysis (CMA) in fetal right aortic arch (RAA) .Method: From May 2017 to May 2018,the routine fetal cardiac screening (four-chamber view,left ventricular outflow tract,right ventricular outflow tract,three vessels trachea view,long axis view of the aortic arch) and the combined cardiac screening adding the subclavian artery view and coronal view of the descending aortic arch to the routine fetal cardiac screening were performed on our hospital's 150 cases whose prenatal ultrasonography showed that their fetuses had suspected fetal aortic arch anomalies.The finds were compared with the results of the postpartum ultrasonography or autopsy results to discuss the value of three vessels trachea view,subclavian artery view and coronal view of the descending aortic arch in the diagnosis of fetal aortic arch anomalies.Meanwhile,traditional karyotype analysis and CMA were performed on 30 samples diagnosed with RAA after delivery,whose prenatal ultrasonography also showed that they had RAA,to evaluate the difference of genome copy number variations (CNVs) in different types of patients with RAA through comparing the detectable rate of those two detection methods.Results: 1.The postpartum ultrasonic cardiograms or autopsies showed that among the 150 selected fetuses,92 cases were positive and the other 58 were negative.The result of the routine fetal cardiac screening showed that 68 cases were positive and 82 cases were negative;the combined cardiac screening adding the subclavian artery view and coronal view of the descending aortic arch to the routine fetal cardiac screening showed that 90 cases were positive and 60 cases were negative.2.The sensitivity,specificity,accuracy,positive predictive value,negative predictive value and AUC of the routine fetal cardiac screening in the diagnosis offetal AAA were respectively 68.48%,91.38%,77.3%,92.6%,64.6%,0.799;the sensitivity,specificity,accuracy,positive predictive value,negative predictive value and AUC of the combined cardiac screening adding the subclavian artery view and coronal view of the descending aortic arch to the routine fetal cardiac screening in the diagnosis of fetal AAA were respectively 95.65%,96.55%,96%,97.8%,93.3%,0.961.The area under the ROC curve of those two methods were compared,and the difference had remarkable statistical significance (Z=5.871,P<0.001) .3.The results of traditional karyotype analysis and CMA showed that:(1)Among 30 fetuses with RAA,3 fetuses with complex chromosome abnormalities (47,XX+21;45,X;47,XY+18) were detected by the traditional karyotype analysis with the detectable rate of 10% (3/30);7 fetuses with abnormalities were detected by CMA with the detectable rate of 23.3% (7/30);microdeletion of 22 q.11.2 was detected in 2fetuses (6.7%) ;other copy number variations with clinical significance were detected in 2 fetuses (microdeletion of 6p21.3 and microdeletion of 9q31.2) .CMA was 13.3%better than the karyotype analysis.(2)Among 24 cases with 24 solitary RAA,3 cases with CNVs were detected (12.5%) ;among 6 cases with non-solitary RAA,4 cases with CNVs were detected (66.7%) .The rate of pathogenic CNVs of non-solitary RAA was higher than that of solitary RAA,and the difference has statistical significance,P<0.05.(3)The sensitivity,accuracy and AUC of the CNVs detected by CMA were respectively 70.0%,90.0%,0.850,which were higher than the sensitivity (30.0%) ,accuracy (76.0%) and AUC (0.650) of the CNVs detected by traditional karyotype analysis.The area under the ROC curve of those two methods were compared,and the difference had remarkable statistical significance (Z=2.449,P<0.05).Conclusions: 1.Three vessels trachea view is an important,fast and effective view for the diagnosis of fetal aortic arch anomalies.2.Subclavian artery view and coronal view of the descending aortic arch have great significance in identifying the types of aortic arch anomalies.3.CMA can detect chromosomal abnormalities that cannot be detected by traditional karyotype analysis,and the clinical application of CMA has great significance for prenatal consultation and postpartum risk assessment.