In vitro animal studies suggest that hyperglycemia impairs fetal cardiac function early in gestation. We aimed to study if evidence of first trimester myocardial dysfunction can be detected in fetuses of women with pregestational diabetes mellitus (DM).
Women with DM underwent fetal echocardiography at 11-14 weeks' gestational age (GA). Cardiac structure was studied in a segmental approach. Cardiac preload, diastolic function, global myocardial performance and placental afterload were studied by Doppler of the ductus venosus (DV), mitral and tricuspid E/A ratios, left and right ventricular Tei index and umbilial artery (UA) respectively. DM patients were matched for GA, UA and DV Doppler with normal controls.
After exclusion of structural cardiac anomalies 60 DM and 60 controls were studied at 12.6 weeks (11.1-13.6). UA and DV pulsatility indices (median 2.22 and 0.99) and nuchal translucency was (median 1.5 mm) were similar between cases and controls. DM patients had lower mitral E/A ratios than controls [0.55±0.08 vs 0.52±0.08, p=0.03). Left and right ventricular Tei indices were significantly higher in diabetics than in controls [0.51±0.08 vs 0.48±0.1; 0.51±0.08 vs 0.45±0.08, p<0.04 and <0.001]. This lower global myocardial performance was due to prolonged myocardial relaxation which was most marked in diabetics with a HbA1c >8. (0.001 for all parameters). No correlation between cardiac Doppler parameters and DV and UA indices were observed.
We demonstrate significant differences in first trimester diastolic myocardial perfomance in fetuses of diabetic mothers compared with non-diabetic controls. In addition, among the diabetics the decrease in myocardial performance was more marked with increasing hyperglycemia, and appears independent of preload and afterload. Our ability to document these changes this early in pregnancy opens potential new avenues to monitor and modify maternal glycemic control before cardiac remodeling such as myocardial hypertrophy develops.
© 2009 Mosby, Inc. Published by Elsevier Inc. All rights reserved.