Study of the natural history of myocardial hypertrophy and its association with hyperinsulinism in infants of diabetic mothers

PURPOSE: To test the hypothesis that myocardial hypertrophy is associated with increased serum insulin levels in children of diabetic mothers and to determine the frequency and timing of this spontaneous regression. METHODS: Seventy-two patients were studied (54 children of diabetic mothers and 18 controls). Diagnosis of myocardial hypertrophy was made by fetal echocardiography. Amniotic fluid insulin levels were obtained from a previous prenatal study on hypertrophic cardiomyopathy, since the participation of the mothers was common to both projects. RESULTS: There were 10 cases of myocardial hypertrophy among children of diabetic mothers (18.52%). Septal thickness was significantly different between the 2 groups (children of diabetic mothers and controls) in the evaluation performed at the age of 1 month (p=0.04). Insulin levels were still increased in children of diabetic mothers until the age of 3 months. During this period insulin levels were significantly higher than those of controls (p=0.003 and p=0.001, at 1 and 3 months, respectively). The association between regression of ventricular septum thickness and the decrease of insulin levels occurred up to the age of 1 month. CONCLUSION: There was spontaneous regression of ventricular septum thickness in children of diabetic mothers during the first 6 months of life. The association between hyperinsulinism and hypertrophic cardiomyopathy was present up to the first month of life.