1Clinical Laboratory, Nippon Kokan Hospital, 2Department of Obstetrics and Gynecology, Nippon Kokan Hospital, 3Koshi Obstetrics and Gynecology Clinic, 4Department of Obstetrics and Gynecology, Tokai University School of Medicine
complete transposition of the great arteries, congenital heart disease, fetal heart screening, tetralogy of Fallot
Fetal cardiac diseases are common congenital anomalies that significantly influence perinatal outcome. Despite increased use of prenatal ultrasonography, however, the rate of detection of congenital heart defect (CHD) before birth remains very low. To improve this rate, we propose more efficient fetal heart screening during routine prenatal evaluation, because 90 percent of CHD cases occur in lower-risk populations. Although the four-chamber view is most commonly used when observing the fetal heart, more than half of all cases of CHD are reported to be overlooked when this is the only view used. Here we report two cases of CHD, (1) complete transposition of the great arteries and (2) tetralogy of Fallot, that were diagnosed from abnormalities detected by the outflow-tract scan, not by the four-chamber view. These cases suggest that detection of CHD in fetal heart screening would be improved by using the outflow-tract scan in addition to the four-chamber view. We therefore propose that observation of outflow tracts be included in fetal heart screening.