Altered diastolic function in asymptomatic infants of mothers with gestational diabetes.

Left and right ventricular filling was studied prospectively in 50 full-term (39.4 +/- 1.3 wk) asymptomatic newborns of mothers with gestational diabetes mellitus (GDM). Their data were compared with those of 80 asymptomatic full-term (39.8 +/- 1.2 wk) infants who served as control subjects. Infants were examined in the immediate newborn period (less than 48 h) and then again at 2-4 and 6-9 wk. Although mean weight, length, and gestational age did not differ, the mean +/- SD left ventricular dimensions during diastole (1.73 +/- 0.15 vs. 1.81 +/- 0.18 cm, P = 0.007) and systole (1.22 +/- 0.15 vs. 1.31 +/- 0.17 cm, P = 0.004) were significantly lower in infants of mothers with GDM compared with control infants. Diastolic measurements suggested a shift from the early diastolic filling of the ventricle to the later period of atrial systole in infants of mothers with GDM. A lower initial one-third area fraction and a higher peak flow velocity and velocity time integral during atrial systole were noted at the mitral valve in infants of mothers with GDM. These changes had resolved by 2-4 wk of age. The altered diastolic filling patterns in infants of mothers with GDM indicate poor myocardial relaxation and/or decreased passive compliance of the ventricular myocardium. These alterations were observed in asymptomatic infants in the absence of left ventricular or septal hypertrophy. If exposed to significant stress such as asphyxia or sepsis, the observed myocardial dysfunction could lead to higher morbidity in these infants.