Objective:To explore the feasibility and prognosis of prenatal ultrasonic diagnosis of fetal isolated vascular ring at 11-13 + 6 weeks. Methods:A total of 36 996 fetuses were selected to compare the results of ultrasound screening at 11-13 + 6 weeks and 20-24 weeks of pregnancy in Guangxi Maternity & Child Healthcare Hospital from January 2016 to January 2020, the reasons for missed diagnosis and misdiagnosis of fetal isolated vascular ring by ultrasonography in the first trimester were summarized. Results:Thirty-five cases were diagnosed as isolated vascular ring in the first trimester, including 19 cases right aortic arch combined with aberrant left subclavian artery with "U-shaped" vascular ring, 7 cases double aortic arch with "O-shaped" vascular ring, and 9 cases aberrant right subclavian artery with "C-shaped" vascular ring. While 155 cases were diagnosed as isolated vascular ring at 20-24 weeks of pregnancy, consisting of 18 cases of combined with aberrant left subclavian artery, 9 cases of double aortic arch, 126 cases of aberrant right subclavian artery and 2 cases of pulmonary artery sling, the diagnosis coincidence rates were 94.74%, 77.78%, 7.14%, 0(Kappa value were 0.97, 0.88, 0.13, 0). For the diagnosis of right aortic arch combined with aberrant left subclavian artery, double aortic arch and aberrant right subclavian artery in the first trimester, the specificities were 99.99%, 100%, 100%, the sensitivities were 100%, 77.78%, 7.14%, the false-positive rates were 0.01%, 0, 0, the false-negative rates were 0, 22.22%, 92.86%, and the Youden′s indices were 0.99, 0.78, 0.07.Conclusions:Right aortic arch combined with aberrant left subclavian artery and double aortic arch have high coincidence rate by ultrasonography in the first trimester, while the diagnostic coincidence rate of isolated aberrant right subclavian artery was low. Ultrasound screening for isolated vascular ring in the first trimester still needs ultrasound examination in the second trimester to exclude the minor cardiac malformations that are difficult to diagnose in the first trimester.

Objective:To assess the value of ultrasonography in the diagnosis of fetal isomerism syndrome in the first trimester.Methods:Sonographic features of 15 fetuses with isomerism syndrome diagnosed in the Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region from January 2015 to March 2020 were reviewed. Ultrasonic characteristics in the first trimester were analyzed, and the ultrasonic characteristics of early mid-trimester and pathological anatomical results were combined for comparison.Results:There were 6 cases of left isomerism syndrome (LIS) and 9 cases of right isomerism syndrome (RIS) in the 15 fetues.Increased nuchal translucency(NT) (≥3.0 mm, 6 cases), reversed A wave in ductus venosus (10 cases), and atrio-ventricular valve regurgitation (14 cases) were found during the first trimester. There were 14 cases with abnormal visceral laterality. Of the 15 fetues, 14 cases with cardiac malformations, including 6 cases of functional single ventricle, 8 cases of complete atrioventricular septal defect (CAVSD), and 12 cases with great artery abnormalities. All of the 6 LIS cases had bradycardia, 3 cases had interruption of inferior vena cava (IVC). Six cases of RIS had juxtaposition of descending aorta and IVC, and 1 case of RIS had total anomalous pulmonary vein drainage. The major structural malformations were consistent with the early mid-trimester ultrasound examination or autopsy. Karyotype and chromosomal microarray were available in 12 cases and all were normal.Conclusions:Isomerism syndrome has high positive rate of fetal aneuploidies ultrasonographic marker, especially with the atrio-ventricular valve regurgitation, but the risk of chromosome abnormality is low. Ultrasound screening for fetal cardiac structural abnormalities is beneficial to the early diagnosis of isomerism syndrom in the first trimester.