Study on the application of ultrasonography in the diagnosis of fetal cardiac structural abnormalities and the relationship between fetal cardiac structural abnormalities with chromosome abnormalities in early pregnancy.

BACKGROUND: To explore the significance of multiple ultrasonic soft indexes such as Nuchal translucency (NT) in detection of cardiac structural malformations and chromosome abnormalities in fetal systematic screening in the first trimester, and to understand the value of combined transvaginal ultrasound (TVUS) in congenital heart disease (CHD) screening.

METHODS: A total of 3,356 pregnant women who underwent early NT screening were screened by systematic ultrasound to monitor and evaluate the sensitivity and specificity of NT, tricuspid valve (TV), ductus venosus (DV) in the diagnosis of fetal CHD. According to the different intervals of NT thickening, the patients were divided into four groups, the detection rates of CHD and abnormal karyotypes in each group were compared, and the consistency of transabdominal and combined transvaginal ultrasonography was compared.

RESULTS: A total of 3,356 cases of early pregnancy were examined by NT. A total of 66 cases of CHD were detected, and the detection rate was 1.97%. Among the 66 CHD cases, 14 cases underwent chromosome karyotype examination and 12 of those cases had abnormal results. With the increase of NT thickness, the detection rates of cardiac structural abnormalities and chromosomal abnormalities all showed a linear increasing trend. The sensitivity of the NT ≥2.5 mm group was as high as 63.64%, and the ductus venosus α wave (DVα) reverse specificity, and the positive likelihood ratio was 99.57% and 53.41%, respectively. The sensitivity of the 3 indicators combined was 66.67%, which was higher than that of any single index, and the area under the receiver operating characteristic (ROC) curve of these 3 indicators combined was the largest (AUC: 0.86). 4. Seventy patients in total were examined by combined TVUS. There is no statistical difference between the two.

CONCLUSIONS: A positive linear correlation was found between NT thickness and the detection rate of fetal cardiac structural abnormality and chromosome abnormality. Early pregnancy NT screening combined with TV blood flow spectrum and DV blood spectrum screenings has high specificity and sensitivity in the diagnosis of CHD. Combined transabdominal and TVUS in early pregnancy can reduce the rates of misdiagnosis and missed diagnosis of fetal CHD.