Mechanical properties of large arteries in mother and fetus during normal and diabetic pregnancy

Objective: To assess the influence of diabetes mellitus on the mechanical w all properties of large maternal and fetal arteries in pregnant women. Methods: Prospective serial monitoring of arterial wall characteristics, us ing ultrasonic phase-locked tracking of vessel diameters and oscillometric brachial blood pressure measurements. Ten pregnant women with insulin-depen dent diabetes mellitus and 15 with gestational diabetes were studied and co mpared with 20 women in uncomplicated gestation. Results: In women with uncomplicated pregnancy, the stiffness index and the elastic modulus of the maternal aorta were lower (both P < 0.05), whereas the pulse amplitude and the strain were higher (both P < 0.05) in the 12th gestational week than in the 6th week postpartum. These differences did not appear in pregnancy complicated by insulin-dependent diabetes. In early ge station, higher aortic stiffness index and elastic modulus (both P < 0.05) and lower pulse amplitude and strain (both P < 0.05) were recorded in gravi dae with insulin-dependent diabetes compared with nondiabetic pregnant wome n; those with gestational diabetes were not detected in early pregnancy. No intergroup or intragroup differences of stiffness index and pulse amplitud e were found in the carotid artery in corresponding gestational ages. In th e fetal aorta, the pulse wave velocity increased during the third trimester of normal gestation (P < 0.05) but not in insulin-dependent diabetic pregn ancy. Conclusion: The difference found concerning the aortic stiffness between wo men with insulin-dependent diabetes during pregnancy and those with uncompl icated pregnancy might be interpreted as an altered cardiovascular adaptati on to pregnancy in women with diabetes.