Fetal cardiac evaluation at 11-14 weeks by experienced obstetricians in a low-risk population

The aim of this study was to evaluate the detection rate of congenital heart diseases (CHD) in a low-risk population by performing cardiac evaluation during the first-trimester screening for chromosomal abnormalities. In this context, the role of four-chamber view, tricuspid regurgitation and abnormal ductus venosus flow in the screening for cardiac anomalies in a low-risk population was also investigated.

The cardiac examination was performed by obstetricians with extensive experience in first- and second-trimester ultrasound (US). Follow-up US evaluations during the second and third trimesters were offered to all patients. In case of abnormal findings during routine assessment, fetal echocardiography was performed by a fetal cardiologist.

Among the 4445 fetuses included in the study, 42 CHD were detected (39 diagnosed prenatally and 3 postnatally). In 27 cases, the fetal cardiologist confirmed the type of CHD diagnosed at US screening. In 1 case, the diagnosis was slightly different in the second trimester, and in 3 of the 26 correctly diagnosed in the first-trimester cases, the CHD developed and progressed in severity. A significant association of major CHD and US first-trimester markers was observed.

First-trimester assessment of the fetal heart is feasible in a low-risk population when performed by experienced obstetricians. However, although most types of CHD can be diagnosed early in pregnancy, some may become apparent later in gestation.