Trends and Outcomes After Prenatal Diagnosis of Congenital Cardiac Malformations by Fetal Echocardiography in a Well Defined Birth Population, Atlanta, Georgia, 1990-1994

Objectives. In this study we useda population-based approach to assess the impact of fetal echocardiography on a well defined birth population with nearly complete ascertainment of cardiac defects. Background. Although fetal echocardiography is being used more frequently in the prenatal diagnosis of congenital cardiac malformations, its impact on the diagnosis and surveillance of cardiac defects has not been described in defined populations. Methods. All stillborn and live-born infants with diagnosed cardiac defects and whose mothers resided in the metropolitan Atlanta area from January 1990 through December 1994 were ascertained through an established birth defects surveillance system. All fetuses with cardiac defects diagnosed prenatally bya pediatric cardiologist were identified from clinical records. The spectrum of cardiac defects, diagnostic trends and adverse fetal outcomes were described. Results. We identified 1,589 infants with congenital cardiac malformations, for a live-birth prevalence rate of 8.1/1,000 (95% confidence interval [el] 7.8 to 8.6). Overall, 97 (6.1%) of these cases of cardiac malformations were diagnosed prenatally. The proportion ofcardiac defects diagnosed prenatally rosefrom 2.6% in 1990 to 12.7% in 1994, a nearly fivefold increase. The proportion of cardiac defects diagnosed prenatally during the study varied by the type of defect, from a low of 4.7% for atrial septal defects to a high of 28% for hypoplastic left heart syndrome. Prenatally diagnosed cardiac malformations were associated with a high incidence ofinfantmortality (30.9%, 95% CI2.4to 5.4) and fetal wastage (17.5%, 95% CI 6.2 to 11.3). Conclusions. These data show that fetal echocardiography is being used increasingly in the prenatal diagnosis of congenital cardiac malformations in metropolitan Atlanta. Few pregnancy terminations were reported as a result of such diagnoses. However, the study had limited power (10%) to detect a meaningful decrease in birth prevalence rates for congenital heart disease. In addition, survival of infants was not improved after prenatal diagnosis with fetal echocardiography.