EFFECT OF DETAILED FETAL ECHOCARDIOGRAPHY AS PART OF ROUTINE PRENATALULTRASONOGRAPHIC SCREENING ON DETECTION OF CONGENITAL HEART-DISEASE

Background Cardiac abnormalities are frequently not detected by routin e ultrasound screening examinations. Although detailed fetal echocardi ography is more sensitive in detection of congenital heart disease, it is used only for high-risk cases. The main aim of this study was to a ssess the prenatal detection of congenital heart disease by detailed f etal echocardiography in an unselected, consecutive group of pregnant women. Methods Between Jan 1, 1993, and Sept 30, 1994, all women who a ttended our antenatal-care unit were routinely offered a detailed feta l echocardiography examination at 18-28 weeks' gestation. 3085 consecu tive women were screened: 2181 were screening cases with no known risk factor for congenital heart disease; 540 had maternal risk factors fo r congenital heart disease, such as a family history or coexisting mat ernal disease; 364 had sonographically detected abnormalities. The exa mination included the four-chamber view, outflow-tract scan, and colou r-flow mapping; doppler and M-mode investigations were also done when appropriate. Findings 46 cases of congenital heart disease were detect ed prenatally by echocardiography-15 in the group with no risk factors , three in the group with maternal risk factors, and 28 in the group w ith sonographic abnormalities. Postnatal assessments found six further cases of congenital heart disease that had not been detected prenatal ly, but these were all minor cases. There were no false-positive diagn oses (sensitivity 85.5%, specificity 100%). The incidence of congenita l heart disease in screening cases with no risk factors and in those w ith maternal risk factors was low (6.9% per 1000, 5.6 per 1000) and si milar to the expected overall incidence of 8.0 per 1000 livebirths in the general population. In the group with sonographic abnormalities co ngenital heart disease was found significantly more often (79.9 per 10 00). Interpretation inclusion of detailed fetal echocardiography as a screening examination has a substantial effect on detection of congeni tal heart disease since a major proportion of prenatally detectable ca ses occur in a low-risk population.