Comparing Ventricular Function in Fetuses of Diabetic and Non-Diabetic Mothers Using Tissue Doppler Imaging

Maternal diabetes is associated with increased teratogenic effects on fetuses; it affects the structure and functions of fetal heart and alters the fetal-placental circulation. Although several articles have demonstrated fetal cardiac malformation and defects in diabetic mothers, ventricular systolic and diastolic function has not been properly investigated, particularly in Iran. The aim of this study was to assess ventricular function using tissue Doppler imaging (TDI) in fetuses of diabetic mothers compared with fetuses of non-diabetic mothers in the Iranian population. Twenty-one diabetic pregnant women at 28 weeks’ gestation were enrolled as the case group, and 35 healthy pregnant women at the same gestation were considered as the control group. Fetal echocardiography, including TDI, was carried out for all cases. The variables measured by echocardiography were as follows: the systolic annular peak velocity (Sa), late-diastolic annular peak velocity (Aa), and diastolic annular peak velocity (Ea) waves on the lateral and septal walls of the left ventricle (LV) at the mitral valve annulus using TDI; mitral inflow E and A waves using pulse Doppler; and inter-ventricular septum thickness using two-dimensional (2D) echocardiography. According to cut-off value of 6.3% for hemoglobin A1C (HbA1c), only one patient with HbA1c = 8 had uncontrolled diabetes. In 20 other patients with controlled diabetes, the mean HbA1c was 4.78 ± 1.22%. There was no significant difference between groups according to maternal age (29.24 ± 5.86 in the case group vs. 28.58 ± 4.42 in the control group, P = 0.6). No significant difference was found in the septal thicknesses between the two groups (P = 0.39). Moreover, there were no statistically significant differences between groups in terms of other echocardiography variables (P > 0.05). We did not find significant differences in ventricular function or ventricular septal thickness in the fetuses of mothers who were referred to our hospital with a previous diagnosis of diabetes mellitus compared with the fetuses of non-diabetic mothers. This could be due to early identification, appropriate treatment, and tightly controlled diabetes in our study population. It should be noted that only pregnant women who were being closely monitored by their gynecologist were referred to us, so there may be some bias in our case selection; moreover, only patients who have taken steps to control their diabetes, so that only one of them had an abnormal HbA1c level. Other possible reasons for our results are over-diagnosis of gestational diabetes by gynecologists and an inadequate number of participants in our study.