Background: Congenital heart disease (CHD) is the most common developmental malformation and the leading cause of neonatal mortality and morbidity. The introduction of fetal echocardiography has made prenatal diagnosis of CHD possible.
Objective: This study was conducted to investigate the impact of fetal echocardiography on the changing disease patterns and outcomes of CHD.
Methods: A retrospective analysis of data from infants with CHD admitted to the neonatal intensive care unit (NICU) of the Asan Medical Center during the time periods was performed. Period I (1994-1996) was considered representative of a period before the introduction of fetal echocardiography, while period II (2004-2006) represented a period of more extensive application of fetal echocardiography.
Results: A total of 164 patients were admitted to the NICU during period I and 320 during period II. The number of infants prenatally diagnosed with CHD was 5 of 164 (3.0%) in period I and 219 of 320 (68.4%) in period II (p < 0.05). The overall accuracy of fetal diagnosis was approximately 92%. Of the 3 CHD categories, there was a greater proportion of infants with 'significant' heart disease in period II than I (47 vs. 32%; p < 0.05). In contrast, there was a smaller proportion of infants with 'simple' heart defects in period II than I (22 vs. 40%; p < 0.05). The proportion of infants with 'complex' heart disease was similar in both periods (28% in period I and 31% in period II). The 1-year survival rate of patients with CHD has improved remarkably with time (70.1% in period I to 88.8% in period II). Multivariate analysis showed prenatal diagnosis and planned delivery in a tertiary NICU are factors affecting CHD outcomes, especially when defects are 'complex' (p < 0.01).
Conclusion: Fetal echocardiography has resulted in an increased frequency of prenatal CHD diagnosis, has altered the disease patterns observed in the NICU, and has resulted in better 1-year outcomes.