Accuracy and limitations of transabdominal fetal echocardiography at 12-15 weeks of gestation in a population at high risk for congenital heart disease

Objective Evaluation of transabdominal fetal echocardiography at 12-15 weeks of gestation. Design Retrospective analysis. Setting Tertiary fetal cardiology unit. Sample Two hundred twenty-nine consecutive fetuses imaged at 12-15 weeks of gestation over a 45-month period. Methods Retrospective analysis of echocardiography and autopsy reports. Main outcome measures Accuracy of early echocardiography for the detection of abnormalities of the cardiac connections. Results Diagnostic images were obtained in 226/229 fetuses (98.7%). Abnormalities of the cardiac connections were detected in 13 fetuses (5.7%) on the initial scan. Where information was available (n = 11), the echocardiographic findings were confirmed at autopsy or postnatally. In two of the 13 cases of congenital heart disease, repeat echocardiography was necessary to provide additional cardiological information. Of the 213 cases in whom a normal initial report was issued, four ( 1.7%) had congenital heart disease diagnosed later in pregnancy (n = 3) or postnatally (n = 1). Three of these fetuses had haemodynamically insignificant ventricular septal defects and one developed a dilated cardiomyopathy later in gestation. Conclusions Transabdominal fetal echocardiography can be performed at 12-15 weeks of gestation permitting accurate early detection of major congenital heart defects in a high risk population. Some forms of congenital heart disease, usually minor, may not be detectable at such an early stage.