The Impact of Fetal Echocardiography on the Prevalence of Liveborn Congenital Heart Disease

Fetal echocardiography allows for early detection of congenital heart disease, and pregnancy termination may be an option in cases of complex defects. In the current study, the most important factors contributing to the diagnosis and termination of affected pregnancies are reviewed and their combined effect on the future prevalence of liveborn congenital heart disease is evaluated. The relative reduction of the prevalence of the most severe forms of congenital heart disease is estimated as the product of the probability that (1) a fetal cardiac screening is performed (p (evaluation)), (2) an affected pregnancy is detected (P (detection)), (3) pregnancy termination is decided following antenatal diagnosis (P (decision)). In areas where termination of pregnancy is a realistic and supported option, a universal sonographic screening of all pregnancies (P (evaluation) = 1), with an average reported sensitivity of 35% and a termination rate of 43% following antenatal diagnosis, would result in a 15% overall reduction of the prevalence of the most severe forms of congenital heart disease. However, wide variability exists regarding the defect-specific estimates (2-50% prevalence relative reduction) due to considerable differences in the reported diagnostic sensitivity and termination rates associated with each heart defect. If an earlier diagnosis could be achieved, which is reported to be associated with an average 1.4-fold increased probability of termination, the overall reduction of the prevalence of congenital heart disease could approach 21%. As the skills of obstetric and pediatric cardiology sonographers improve, fetal echocardiography is expected to have a substantial impact on the future epidemiology of liveborn congenital heart disease.