Diabetes mellitus in pregnancy and the assessment of umbilical artery waveforms using pulsed Doppler ultrasonography.

The utility of Doppler ultrasonography as a means of assessing potential alterations of vascular resistance prior to fetal or maternal compromise is very attractive. We investigated this relationship by prospectively performing Doppler studies of the fetal umbilical artery in 56 diabetic patients, 14 of whom had varying degrees of vascular complications. When regression curves were established for the S/D ratio, the Pourcelot index, and the resistance index of the fetal umbilical artery, the mean Doppler values were higher in diabetic patients with vasculopathy than in nondiabetic control patients or in diabetic patients without vasculopathy. The third trimester S/D ratio was greater than 3.0 in almost 50% of patients with vasculopathy