Background and Objectives: Congenital heart disease is a leading cause of infant morbidity and mortality from birth defects with an estimated incidence of 6-12 per 1000 live births. The objectives of the study are to determine the prevalence of congenital cardiac anomalies in and around Cuddalore district, to ascertain the importance of four chamber view and Outflow tract views in the evaluation of congenital cardiac anomalies, to evaluate the efficacy and reliability of fetal echocardiography as a diagnostic tool in the detection of congenital heart disease and to follow up and evaluate the outcome of fetuses diagnosed with congenital heart disease.
Materials and Methods: Fetal echocardiography was done as a hospital based prospective study in randomly selected 500 antenatal women referred for routine antenatal ultrasound for a period of 2 years.
Results: The prevalence of congenital heart disease by fetal echocardiography was 2.2%.Out of the 11 cardiac anomalies, 7 cases of structural cardiac anomalies were identified and 4 were non structural defects. We did not find any rhythm disorder in our study. Endocardial cushion defect was the most common cardiac anomaly in our study followed by echogenic cardiac focus. Majority of the antenatal women with cardiac anomalies were in the gestational age of 28-32 weeks. Majority of the antenatal women with cardiac anomalies did not have any high risk factors and extracardiac anomaly. Out of 11 cases with cardiac anomalies, 6 were terminated, 3 cases were delivered by vaginal delivery and 2 cases underwent LSCS. 2 cases were found to be normal and 3 cases were confirmed with cardiac anomaly on postnatal echocardiography. Additionally 3 cases were found to have cardiac anomaly on postnatal echocardiography. The sensitivity of Fetal echocardiography for cardiac anomalies was 75%, specificity was 99.59%, the positive predictive value was 81.8%, and the negative predictive value was 99.38% with an accuracy rate of 99%.
Conclusion: Routine fetal cardiac ultrasound using four chamber and outflow-tract views enables the detection and characterization of most of the cardiac anomalies. With moderate sensitivity and high specificity, Fetal echocardiography is a reliable prenatal diagnostic tool for cardiovascular problems with high accuracy. Timely diagnosis of cardiac anomalies allows the family to choose whether to continue pregnancy or terminate it. Since most cardiac anomalies occur without any risk factor, routine prenatal ultrasound almost misses an isolated cardiac anomaly, hence routine fetal echo in all antenatal cases must be done to rule out Congenital heart disease.