P292: Early diagnosis of congenital heart defects (CHD) in high-risk patients

Abstract

To establish the validity of fetal echocardiography between 12 and 16 weeks gestation for early reassurance of normal anatomy and for the diagnosis of CHD in high-risk pregnant women. Transvaginal and transabdominal echocardiography was performed in 341 high-risk fetuses: increased nuchal translucency (n = 148), extracardiac anomalies (58), chromosomal abnormalities (5), family history of CHD (46), pregestational diabetes (41), teratogen exposure (4) and genetic sonography (38). Examinations were considered complete when were identified: four-chamber, outflow tracts, venous return and transvalvular Doppler. The results were compared with those observed in later scans, in the autopsy and/or in the neonatal examination. This is a prospective study. The rate of complete visualization was 94% (321/341). The overall rate of CHD rose to 26% (n = 63). In 54 (86%) the diagnosis was made in early gestation. All were major anomalies. Nine CHD were missed at early examination (4 ventricular septal defects, 3 complete atriventricular defects, 2 tetralogy of Fallot). Normality was confirmed in the remaining. There were no false positive. In 37 cases (10%) the follow-up was incomplete. Early fetal echocardiography is feasible in most cases and should be offered to high-risk pregnant women allowing the diagnosis of most major CHD. It must be complemented with later scans because of false negative cases, mainly septal defects.