Analysis of prenatal diagnosis by ultrasonography and clinical outcome of isomerism syndrome in the first trimester / 中华超声影像学杂志

ABSTRACT

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.