Severe preeclampsia and cerebral blood volume response to postural change

Abstract

Objective To compare the cerebral blood volume response, measured by near-infrared spectroscopy, to a change in maternal posture in pregnant women with and without the hypertensive disorders of pregnancy. Methods Normotensive ( n = 13), chronic hypertensive ( n = 7), pregnancy-induced hypertensive ( n = 9), and preeclamptic ( n = 15) women were studied cross-sectionally. The change in cerebral blood volume in response to a change in maternal posture from the left lateral to sitting position was quantified. Results In the normotensive, chronic hypertensive, and pregnancy-induced hypertensive groups there was a fall in median (interquartile range) cerebral blood volume of 0.18 (−0.21, −0.15), 0.11 (−0.26, −0.09), and 0.089 (−0.10, −0.049) mL/100 g, respectively. Conversely, in the preeclamptic group there was a rise in median cerebral blood volume of 0.13 (−0.20, 0.15) mL/100 g. Of these, six of the nine women with a median rise in cerebral blood volume of 0.15 mL/100 g (0.13, 0.16) required intravenous antihypertensive therapy, volume expansion, and delivery by cesarean within 48 hours. Conversely, none of the preeclamptic women ( n = 6) with a median fall in cerebral blood volume of 0.22 mL/100 g (−0.30, −0.18) required these emergency measures. Conclusion The cerebral blood volume response, measured noninvasively by near-infrared spectroscopy, provides additional evidence of altered cerebral hemodynamics in women with preeclampsia.