Color Doppler Patterns' Recognition Indicative of Congenital Heart Defects at the First-Trimester Referral Scan.

Background/

Objectives

First-trimester referral scans in high-risk pregnancies are performed by expert fetal medicine operators using an extended protocol that includes direct fetal heart assessment. This study evaluated inter-operator agreement in characterizing the four-chamber view (4CV) and three vessels and trachea view (3VTV) using color Doppler during such scans in both normal and abnormal cases.

Methods

Two independent operators and a fetal cardiologist, all blinded to final diagnoses, retrospectively reviewed 2D images and video clips of the 4CV and 3VTV in 90 fetuses (45 with congenital heart disease [CHD] and 45 controls). The 4CV was classified into four patterns: (1) two atrioventricular (A-V) inflows of similar size, (2) one A-V inflow filling two ventricles, (3) one A-V inflow filling one ventricle, and (4) two A-V inflows with disproportion. The 3VTV was assessed for (1) normal V-sign, (2) abnormal vessel number, (3) abnormal vessel dimension, (4) abnormal spatial relationships, and (5) ductal dependence. Agreement was measured using Cohen's Kappa.

Results

Perfect agreement (K = 1) was seen in normal cases. In CHD cases, inter-operator and operator-cardiologist agreement was almost perfect for 4CV (K = 0.83-0.96) and substantial for 3VTV (K = 0.77-0.80). The lowest agreement occurred with ventricular disproportion in 4CV and abnormalities in vessel number and size in 3VTV.

Conclusions

Expert operators show strong agreement in interpreting 4CV and 3VTV patterns in first-trimester scans using color Doppler. However, certain abnormalities-particularly ventricular disproportion and vessel anomalies-remain challenging to consistently interpret.