Fetal diagnosis of fatal congenital heart disease

The identification of the structure of the fetal heart became possible in the early 1980s as the resolution of ultrasound equipment improved. At that time, use of fetal echocardiography was confined to mothers whose fetuses were at increased risk of developing congenital heart disease, although only 10% of congenital heart disease occurs in this group. In 1985 a French group suggested that obstetricians involved in routine scanning be taught a simplified form of heart scanning, which made it possible to screen the general pregnant population for major anomalies. This form of heart scanning involved the examination of one section of the heart, the four-chamber view, and this approach greatly increased the potential impact of fetal echocardiography. As a result of the success of this program in both the United Kingdom and France, a continually increasing proportion of major cardiac defects are detected prenatally. There is almost no form of structural heart disease seen in a four-chamber projection during a routine scan that will not result in the eventual death of the child or young adult. Surgery may delay or defer this event, depending on the anatomic anomaly, but in general the outlook for affected children and their chance of reaching healthy adult life is poor. Most parents who learn this before 20 weeks of pregnancy will elect to interrupt the pregnancy. As a result a decline in the number of postnatal cases of some defects, such as the hypoplastic left-heart syndrome, can be documented in postnatal life.