Abstract: | Objective: To detect the structural and functional changes of fetal hearts in diabetic pregnancies by using Doppler echocardiography. Methods: This prospective study included 119 pregnant women divided into three groups. Group 1 included 47 pregnant patients with pre-existing diabetes mellitus (DM), group 2 included 40 patients with gestational diabetes and group 3 included 32 non-diabetic pregnant women. M-mode echocardiography was used to measure the thickness of the fetal ventricular walls and interventricular septum. The mitral and tricuspid early (E) and late (A) diastolic velocities and the ventricular shortening fraction were measured. Results: HbA1c % was significantly lower in gestational diabetes group compared with the pre-existing diabetes group. The interventricular septum was significantly thicker in the pre-existing diabetes group compared with other groups. Tricuspid and mitral E/A ratios were significantly lower in the pre-existing diabetes group compared with gestational diabetes and control groups. Moreover, there were no significant differences in the tricuspid and mitral E/A ratios between gestational diabetes group and the control group. The right and left ventricular shortening fractions were similar in the three groups. Conclusion: Fetuses of women with well-controlled gestational diabetes lack the diastolic dysfunction that is present in fetuses of women with pre-existing diabetes |