Effect of pregestational diabetes mellitus on fetal cardiac function and structure.

OBJECTIVE: Fetuses of diabetic pregnancy experience cardiomyopathy, the intracardiac cause of which is understood poorly. The aim of this study was to assess the interrelation between cardiac functional and structural changes in fetuses of mothers with pregestational diabetes mellitus. STUDY DESIGN: Twenty-six mothers with pregestational diabetes mellitus were recruited prospectively to have a fetal echocardiogram at 13, 20, and 36 weeks of gestation to assess cardiac function and structure. For comparison, 30 healthy control subjects were recruited at each gestational age. RESULTS: In the first trimester, there was evidence of poorer fetal cardiac diastolic function among the diabetic cohort (lower left early/atrial ratio, longer isovolumetric relaxation time and higher left myocardial performance index; P < .05). In the third trimester, the fetal interventricular septum and the right ventricular free wall were thicker in the diabetic cohort (P < .05). CONCLUSION: In fetuses of pregestational diabetic pregnancy, sonographic evidence of altered cardiac function is evident before ultrasound evidence of cardiac structural changes. This suggests that altered cardiac function may precede cardiac structural changes in fetuses of pregestational diabetic pregnancy.