Approximately 3-6% of newborns born to diabetic mothers (NNMD) have cardiovascular abnormalities. Hypertrophic cardiomyopathy (HCM) is the most common cardiac disorder, accounting for 40% of cardiovascular anomalies. Its incidence, often underestimated due to the frequency of asymptomatic forms, varies between 30% and 40%.NNMD HCM is mainly induced by fetal hyperinsulinism secondary to maternal hyperglycemia. It is characterized by disproportionate hypertrophy of the heart: hypertrophy of the interventricular septum (IVS) due to its high insulin receptor content, and of the free ventricular walls. Clinically, HCM can be completely asymptomatic, as seen on cardiac ultrasound, or manifest as congestive heart failure due to obstruction of the left ventricular ejection pathway. Whatever its severity, cardiac hypertrophy is transient, with echocardiographic resolution around six months of age in all cases.