Cardiac function in fetuses of poorly controlled pregestational (pre‐existing) diabetic pregnancies

Abstract

Background: Cardiac impairment is frequently found in fetuses of diabetic mothers. Poor diabetic control has been implicated as one of the cause for cardiac dysfunction, but it is still controversial.Aim: To assess the cardiac function in fetuses of well‐controlled and poorly controlled pregestational (pre‐existing) diabetic pregnancy in the third trimester.Methods: Women with pregestational diabetes (Type 1 and 2) were enrolled at 30–36 weeks. Right‐, left‐ventricular septal wall and interventricular septal wall thickness were measured by M‐mode at end‐diastolic phase. At the mitral and tricuspid valves inflow, the ratio between early ventricular filling and active atrial filling (E/A) at both atrioventricular valves were measured by Doppler echocardiography. Peak velocities of ascending aorta and pulmonary artery were assessed. Angle of isolation was kept at less than 20°. Results from women with poorly controlled diabetes (HbA1c > 6.5%) were compared with those whose diabetes were satisfactorily controlled (HbA1c ≤ 6.5%).Results: A total of 15 women were included in this study. Six had well‐controlled diabetes and the other seven had poorly controlled diabetes. HbA1c in the poorly controlled group was 7.3% and in the well‐controlled group was 5.4% (P < 0.001). There was no difference between the groups in cardiac size, interventricular septal wall thickness, ejection fraction, aorta and pulmonary artery peak flow velocities. The right atrioventricular E/A ratio was significantly lower among the poorly controlled DM pregnancies (0.71 vs. 0.54; P < 0.05). This reflected an impaired right ventricular compliance in fetuses of poorly controlled diabetic mothers.Conclusion: Fetuses of poorly controlled diabetic mothers had lower atrioventricular E/A ratio. This may be due to impaired right ventricular compliance.