Effect of Prenatal Diagnosis on Outcome in Patients With Congenital Heart Disease

Abstract

After completing this article, readers should be able to: 1. List the most frequent prenatally diagnosed forms of congenital heart disease. 2. List the fetal indications for echocardiography. 3. List the maternal indications for echocardiography. 4. Review the findings of studies comparing the outcome of prenatally versus postnatally diagnosed newborns who have congenital heart disease. 5. List the advantages of prenatal diagnosis of congenital heart disease. Congenital heart disease (CHD) continues to be a major source of neonatal mortality. Since the development of echocardiographic screening for fetal cardiac anatomy in the 1980s, an increasing number of affected newborns are identified prior to delivery. (1) A recent study in a population that had risk factors for CHD found that the sensitivity of fetal echocardiography was 38%, with a false-positive rate of only 0.05%. (2) However, when performed by skilled operators viewing outflow tracts in addition to the four-chamber view, an accuracy as high as 96% has been reported. (3) These prenatal diagnoses are heavily skewed toward more severe CHD, with disorders of the atrioventricular junction (endocardial cushion defects), univentricular hearts, and hypoplastic left heart syndrome (HLHS) being the most common (Table 1). | Diagnosis | Proportion of All Fetal Diagnoses | Proportion of CHD in Newborns in Study | |:-------------------------------------------:| --------------------------------- | -------------------------------------- | | Hypoplastic left heart syndrome | 31% | 15% | | Atrioventricular septal defect | 30% | 25% | | Univentricular heart | 20% | 9% | | Pulmonary atresia intact ventricular septum | 8% | 5% | | Total anomalous pulmonary venous return | 0.3% | 1% | | Tetralogy of Fallot | 9% | 28% | | Transposition of the great arteries | 1.7% | 17% | Table 1. Relative Frequencies of Congenital Heart Defects (CHD) at Fetal Diagnosis and Seen At Birth* The ability to identify the most severe forms of CHD prior to delivery has changed the population of liveborn infants who have CHD. Prenatal diagnosis allows for extensive parental counseling and coordination of care. The fetal diagnosis of CHD prompts genetic testing to identify chromosomal abnormalities, which are found in 10% of cases, and a detailed anatomic evaluation to assess associated extracardiac anomalies, which coincide in 15% of cases. (1) In cases of poor prognosis, early prenatal diagnosis gives the parents the option of terminating …