Role of routine fetal echocardiography in an unselected group of pregnant women for prenatal detection of cardiac malformations

OBJECTIVES: We investigated the potential for improvement in prenatal detection of congenital heart disease (CHD) by routinely performing detailed fetal echocardiography (FE) in all pregnant women. METHODS: Following routine obstetric sonography, 1445 unselected pregnant women were prospectively subjected to FE at gestational ages between 16 and 24 weeks, or at first visit, if they presented later. Maternal or fetal factors, conventionally known to be associated with risk of CHD, were noted. The prevalence and detection rates of cardiac abnormalities were determined, and confirmation of findings by postnatal follow-up was done to ensure accuracy of FE. Prevalence of CHD was compared in pregnancies with or without conventional risk factors. RESULTS: The overall prevalence of CHD was 8.3 per 1000; only 2 CHD cases belonged to the high maternal risk group, while 10 cases were observed without maternal risk factors. Cardiac malformations were suspected in 14 fetuses during obstetric scan; but, only 5 of them had CHD, remaining 9 had structurally normal hearts. 50% of CHD cases occurred in pregnancies not associate with any (fetal or maternal) risk factor. The sensitivity, and specificity for prenatal CHD detection were 91.7% and 100% respectively. CONCLUSIONS: Our study indicates that a substantial proportion of CHD cases occur in women not having high risk of giving birth to children with CHD. FE is a highly sensitive and specific test with strong predictive values. We recommend that FE should be done in every pregnancy.