Pre-gestational Diabetes and Congenital Heart Defects
Congenital heart defects (CHD) comprise a wide range of malformations of the heart (i.e., atrial and ventricular chambers and septa, and atrioventricular and semilunar valves) and great vessels (i.e., the great arteries and systemic and pulmonary veins), reflecting the complexity of developmental processes and potential disturbances in morphogenesis of the cardiovascular system. The first published report on the spectrum of CHD phenotypes was an atlas of a systematic classification of CHD based on pathophysiologic considerations of 1,000 cases by Maude Abbott in 1936.1 Since then, the nomenclature and classification of CHD phenotypes have evolved with the development of surgical repairs and conduct of population-based studies into possible causes using methods that account for potential etiologic heterogeneity among specific CHD phenotypes and among groupings of phenotypes of similar developmental origin.2-7 More recently, the National Birth Defects Prevention Study further developed the classification of CHD to account for variation of phenotypes based on the complexity of cardiac lesions present (i.e., simple, associations, complex) as well as for the presence of disorders in other organ systems (i.e., isolated or multiple/complex pattern).8 These developments nomenclature and classification in turn have facilitated more reliable assessments of trends in population-based prevalence of specific phenotypes of CHD9, 10 and standardized research methods for the purpose of identifying modifiable risk factors and potential prevention interventions for CHD.
- Received May 6, 2016.
- Accepted May 9, 2016.