Transcranial assessment of maternal cerebral blood flow velocity in normal VS pre-eclamptic women (variation with maternal posture). A preliminary study.

To compare the effect of a change in maternal posture on maternal cerebral blood flow velocity assessed transcranially in a normal vs a pre-eclamptic group 5 normotensive and 5 pre-eclamptic patients had maternal middle cerebral artery (MCA) blood flow velocity assessed in 2 positions supine and sitting upright using a 2 mHz transcranial doppler ultrasound. Comparison was then made of the effect of a change in posture on cerebral blood flow velocity in both groups using paired student-t test. Normotensive women showed minimal change in MCA blood flow velocity while pre-eclamptic women showed a 20% rise in all aspects of MCA blood flow velocity from supine to sitting. In pre-eclamptic patients MCA blood flow velocity which showed a significant rise with change in posture is not accompanied by significant changes in blood pressure and so is not a secondary response to a change in cardiac output by may be a primary effect related to local circulatory changes. Transcranial assessment of maternal cerebral blood flow velocity performed in normotensive and various hypertensive groups showed significant variation with change in posture in the pre-eclamptic group.