Prenatal Detection of Congenital Heart Defects: Impact of Screening with Five-Chamber View Versus Four-Chamber View
Keywords:
Congenital heart defects, prenatal ultrasound, five-chamber view, detection rate, conotruncal anomaliesAbstract
Introduction: The four-chamber view (4CV) of the fetal heart is standard in obstetric ultrasound. Adding the five-chamber view (5CV) and outflow tracts may increase detection of conotruncal anomalies, but routine implementation is debated.
Methods: Literature search for prospective studies comparing 4CV alone versus 4CV+5CV/outflow tracts screening in low-risk populations. Primary outcome: prenatal detection rate of major congenital heart defects (CHD) confirmed postnatally.
Results: Thirteen studies (n=240,000 fetuses) were included. The detection rate of major CHD with 4CV alone was 42%; adding 5CV and outflow tracts increased detection to 66% (p<0.001). The false-positive rate rose from 0.8% to 1.9%. Detection of transposition of great arteries improved most (from 15% to 71%).
Discussion: Extended cardiac views significantly improve detection of specific CHD, especially conotruncal defects. Additional training and scanning time (approximately 2 minutes) are required. The trade-off is a small increase in false positives.
Conclusions: Adding the 5CV and outflow tracts to routine second-trimester ultrasound doubles detection of major CHD in low-risk pregnancies and should be considered standard practice where sonographer expertise exists.
