Cerebrovascular Hemodynamics in Chronic Hypertensive Pregnant Women Who Later Develop Superimposed Preeclampsia

Abstract

Objective: We have previously shown that normotensive pregnant women who later develop preeclampsia demonstrate lower baseline pulsatility index (PI) and resistance index (RI) but normal vasodilatory responses to stimulation tests. In the current study, we tested the hypothesis that women with chronic hypertension who later developed superimposed preeclampsia behave similarly.

Methods: Transcranial Doppler ultrasound was performed on 17 women with chronic hypertension during the second trimester of pregnancy to measure middle cerebral artery (MCA) velocities. Superimposed preeclampsia developed in seven patients (SUPER group) while the rest did not develop preeclampsia (CHT group). Measurements were performed in the left lateral position at baseline on room air, during 5% CO₂ inhalation, and during a 2-minute isometric handgrip test. Blood pressure, heart rate, 02 saturation, and end-tidal PCO₂ were recorded with each Doppler measurement. Mean PI, RI, and cerebral perfusion pressure (CPP) at each time were compared using two-way repeated measures analysis of variance. Statistical significance was set at P < .05.

Results: The women who developed superimposed preeclampsia did this an average of 8.7 ± 1.3 weeks after the study. MCA PI and RI were lower, and CPP higher, in the SUPER group compared to the CHT group (0. 64, 0.46, and 80.7 vs 0. 74, 0.51, and 63.6, respectively; P<.05). Both maneuvers caused reduction in MCA PI and RI in both groups, whereas CPP increased only in the SUPER group.

Conclusions: These findings suggest that women destined to develop preeclampsia have cerebral hemodynamic changes that predate the development of overt preeclampsia.

Keywords

Middle cerebral artery chronic hypertension superimposed preeclampsia transcranial Doppler ultrasound

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References

1. Sheppard BL , Bonnar J . An ultrastructural study of utero-placental spiral arteries in hypertensive and normotensive pregnancy and fetal growth retardation. Br J Obstet Gynaecol 1981;88:695-705.

2. Khong TY , De Wolf F , Robertson WB , Brosens I . Inadequate maternal vascular response to placentation in pregnancies complicated by pre-eclampsia and by small-for-gestational age infants. Br J Obstet Gynaecol 1986;93:1049-1059.

3. Ringelstein EB , Otis SM . Physiological testing of vasomotor reserve. In: Newell DW , Aaslid R , eds. Transcranial Doppler. New York: Raven, 1992:83-99.

4. Hartl WH , Furst H . Application of transcranial Doppler sonography to evaluate cerebral hemodynamics in carotid artery disease. Comparative analysis of different hemodynamic variables. Stroke 1995;26:2293-2297.

5. Linkis P , Jorgensen LG , Olesen HL , Madsen PL , Lassen NA , Secher NH . Dynamic exercise enhances regional cerebral artery mean flow velocity. J Appl Physiol 1995;78:12-16.

6. Imms FJ , Russo F , lyawe VI , Segal MB . Cerebral blood flow velocity during and after sustained isometric skeletal muscle contractions in man. Clin Sci (Colch) 1998;94:353-358.

7. Riskin-Mashiah S , Belfort MA , Saade GR , Herd AJ . Transcranial Doppler measurement of cerebral velocity indices as a predictor of preeclampsia. Am J Obstet Gynecol 2002;187:1667-1672.

8. Riskin-Mashiah S , Belfort MA . Cerebrovascular hemodynamics in pregnant women with mild chronic hypertension. Obstet Gynecol 2004;103:294-298.

9. National High Blood Pressure Education Program . Working group report on high blood pressure in pregnancy. Am J Obstet Gynecol 2000;183 Suppl 1.

10.

10. Aaslid R , Lundar T , Lindegaard KF , Nornes H. Estimation of cerebral perfusion pressure from arterial blood pressure and transcranial Doppler recording. In: Miller JD , Teasdale GM , Rowan Superimposed Preeciampsia JO , Galbraith SL , Mendelow AD , eds. Intracranial pressure. Vol. 6. Berlin: Springer-Verlag, 1986:226-229.

11.

11. Belfort MA , Tooke-Miller C , Varner M , et al. Evaluation of a noninvasive transcranial Doppler and blood pressure-based method for the assessment of cerebral perfusion pressure in pregnant women. Hypertens Pregnancy 2000;19:331-340.

12.

12. Kyle PM , de Swiet M , Buckley D , Serra Serra V , Redman CW . Noninvasive assessment of the maternal cerebral circulation by transcranial Doppler ultrasound during angiotensin IL infusion. Br J Obstet Gynaecol 1993;100:85-91.

13.

13. Serra-Serra V , Kyle PM , Chandran R , Redman CW . Maternal middle cerebral artery velocimetry in normal pregnancy and postpartum. Br J Obstet Gynaecol 1997;104:904-909.

14.

14. Belfort MA , Tooke-Miller C , Allen JC Jr , et al. Pregnant women with chronic hypertension and superimposed pre-eclampsia have Riskin-Mashiah and Belfort higher cerebral perfusion pressure. Br J Obstet Gynaecol 2001;108:1141-1147.

15.

15. Belfort MA , Tooke-Miller C , Allen JC Jr , et al. Changes in flow velocity, resistance indices, and cerebral perfusion pressure in the maternal middle cerebral artery distribution during normal pregnancy. Acta Obstet Gynecol Scand 2001;80:104-112.

16.

16. Easterling TR , Benedetti TJ , Schmucker BC , Millard SP . Maternal hemodynamics in normal and preeclamptic pregnancies: A longitudinal study. Obstet Gynecol 1990;76:1061-1069.

17.

17. Bosio PM , McKenna PJ , Conroy R , O'Herlihy C . Maternal central hemodynamics in hypertensive disorders of pregnancy. Obstet Gynecol 1999;94:978-984.

18.

18. Riskin-Mashiah S , Belfort MA , Saade GR , Herd JA . Cerebrovascular reactivity in normal pregnancy and preeclampsia. Obstet Gynecol 2001;98:827-832.