Background: Fetal echocardiography (FECG) is a key screening tool for prenatal cardiac abnormalities. Herein, we examined the ultrasonic factors determining prenatal ultrasonic diagnosis of isolated ventricular septal defect (IVSD).

Methods: The diagnostic role of ultrasonic factors was investigated in patients in middle or late pregnancy, diagnosed with IVSD by FECG and confirmed using postnatal echocardiography.

Results: One hundred and six patients with IVSD were enrolled; the majority had perimembranous VSD. The combined imaging mode of 2 dimentionalechocardiography (2DE) and color doppler flow imaging (CDFI) showed the highest rate (56.6%) of IVSD detection, while CDFI was more efficient than 2DE (32.1% vs. 11.3%). The single-view mode was more efficient than multiple-view mode (75.5% vs. 24.5%). The highest efficient mode to detect IVSD was achieved using combined imaging mode on the single view of the left ventricular outflow tract view (LVOTV) (28.3%). FECG correctly classified 71.7% of fetal IVSD. There was a significant difference of accuracy rate in classifying IVSD among the three different imaging modes (χ2=7.141, P<0.05). The single imaging mode of CDFI and the mode of CDFI combined with 2DE correctly classified 75.9% and 75.0% of fetal IVSD, respectively. LVOTV was the most accurate view of fetal IVSD classification (85.2%; χ2=15.782, P<0.05). There was no difference in accuracies of IVSD classification among multiple-view modes (χ2=2.343, P>0.05) or between single-view mode and multiple-view mode (χ2=0.32, P>0.05).

Conclusion: Single LVOTV in CDFI or CDFI combined with 2DE of FECG were the most effective diagnostic modes for fetal IVSD diagnosis.