Assessment of cerebral hemodynamics in pregnant women by internal carotid artery pulsed Doppler velocimetry.

To date, no studies have been done of serial changes in maternal cerebral hemodynamics during pregnancy. We used the noninvasive method of Doppler velocimetry to assess cerebral hemodynamics in pregnant women. Velocimetry measurements of the internal carotid artery were performed in 17 normal nonpregnant women and 77 women with uncomplicated pregnancies with a 4 MHz pulsed Doppler ultrasound system. Peak systolic and mean velocities in the first and second trimesters were almost the same as those in nonpregnant women, whereas they became slower in the third trimester. Pulsatility index from 4 to 31 weeks' gestation was significantly higher than in nonpregnant women, but fell to the nonpregnant value after 32 weeks. Doppler velocimetry was found to be an extremely useful method of cerebrohemodynamic evaluation in pregnant women.