The value of outflow tract flow tracing in early pregnancy in the screening of structural malformations of fetal cardiac great arteries.

Background: To explore the application value of outflow tract "" blood flow in screening fetal cardiac macrovascular structural malformations in early pregnancy.

Methods: A total of 3,356 pregnant women who underwent nuchal translucency (NT) screening during early pregnancy in the prenatal diagnosis center of General Hospital of Ningxia Medical University from January 2017 to December 2018 were taken as the research objects, and the fetuses were systematically screened by ultrasound. The display of four chamber cardiac blood flow, X-shaped blood flow of main pulmonary artery, V-shaped blood flow of three vessel trachea and "" shaped blood flow of outflow tract were observed and recorded. Fetal autopsy was performed after informed consent of those who terminated pregnancy. Follow up of fetuses and physical examination of newborns.

Results: A total of 3,356 cases underwent NT examination in early pregnancy, with an average age of 29.18±4.55 years and crown-rump length (CRL) (6.62±0.89 cm). A total of 66 cases of congenital heart disease (CHD) were detected, and the detection rate was 1.97%. There were 15 cases of conus trunk malformation, accounting for 22.7% of the total incidence of CHD. The sensitivity and the receiver operating characteristic (ROC) curve area (AUC =0.659) of "" blood flow of outflow tract in early pregnancy were higher than those of "X" Cross blood flow of main pulmonary artery and "V" blood flow of three vessel trachea.

Conclusions: "" Doppler superimposed blood flow in the outflow tract has high sensitivity in the screening of fetal cardiac macrovascular malformations, and has good predictive value for CHD. It can be used as a standard to evaluate whether fetal heart is accompanied by conus trunk malformation.