Side-to-side differences in transcranial Doppler parameters in normotensive and preeclamptic pregnant women.

Abstract

This study was undertaken to investigate whether women with preeclampsia demonstrate larger side-to-side velocity differences in the middle cerebral artery (MCA) compared with normotensive pregnant women. Forty-one preeclamptic women and 50 normotensive pregnant women were studied during the third trimester. Transcranial Doppler ultrasound was used to measure peak, end-diastolic, and mean velocities in both MCAs. An asymmetry index was calculated as 100 x Rt-Lt//(Rt+Lt)/2, for each of the following parameters: mean velocity (Vm), pulsatility index (PI), and cerebral perfusion pressure (CPP). Student t test, Pearson correlation, and regression analysis were used. Significance was taken as P<.05. Both normotensive and preeclamptic pregnant women showed good correlation between Rt and Lt MCA Vm (R>0.8, P<.0001), PI (R>0.6, P.0001), and CPP (R>0.8, P<.0001). There were no differences in the asymmetry index for Vm, PI, or CPP between the two groups. Preeclampsia does not appear to induce greater side-to-side velocity differences in the MCA distribution.