Interventricular septal thickness in fetuses of diabetic mothers.

Sixty-four diabetic women had their fetuses studied by M-mode echocardiogram between 20-41 weeks of gestation. The mean septal size during both diastole and systole increased in a linear fashion with advancing gestational age in both the normal and diabetic groups. Ventricular septal hypertrophy (ie, more than 2 standard deviations above the normal mean) was present in 48 of 64 (75%) of the fetuses of diabetic women. The ratio of septal size to the anteroposterior cardiac dimension was significantly greater in the diabetic than in the normal group (12 versus 8%; P less than .05). The anteroposterior cardiac dimension indexed to the estimated fetal weight was also greater in the diabetic group. Because both septum and cardiac dimension are larger with maternal diabetes, there may be a specific diabetic cardiomyopathy that originates in utero.