A case of fatal neonatal dilated cardiomyopathy in an infant of a diabetic mother.

Dilated cardiomyopathy (DCM) is the most common pediatric cardiomyopathy and a leading cause of heart failure and cardiac transplantation in children. While a rare complication of maternal diabetes, the dilated phenotype of Infant of a Diabetic Mother (IDM) cardiomyopathy carries a high risk of morbidity and mortality. We report a term female neonate born to a mother with poorly controlled gestational diabetes (HbA1c 8.0%) who developed severe cardiogenic shock within 24 hours of life. Echocardiography confirmed DCM with profound biventricular dysfunction (initial left ventricular ejection fraction [LVEF] 28%, deteriorating to <17% within 5 days) and associated left ventricular non-compaction (LVNC) morphology. Despite maximal medical therapy, the infant's condition deteriorated, and she died on day 11 of life. Comprehensive diagnostic workup for alternative etiologies was limited by the rapid clinical course. This fatal case highlights the potential severity of the dilated form of IDM cardiomyopathy, which can be rapidly progressive and refractory to treatment. It underscores the critical importance of optimal glycemic control in pregnancy while acknowledging that alternative genetic or metabolic etiologies cannot be definitively excluded. This presentation should be recognized as a high-risk clinical entity distinct from the more common and often transient hypertrophic form.