Alterations in uteroplacental blood flow precede hypertension in preeclampsia at high altitude. Zamudio, Stacy, Susan K. Palmer, Thomas E. Dahms, Jonathan C. Berman, David A. Young, Lorna Grindlay Moore. Department of Anesthesiology, University of Colorado Health Sciences Center, Denver, CO 80262, Women's Health Research Center, University of Colorado Health Sciences Center, Denver, CO 80262, Department of Anthropology, University of Colorado at Denver, Denver, CO 80217-3364, Department of Anesthesiology, St. Louis University Medical Center, St. Louis, MO 63110, Department of Preventive Medicine and Biometrics, University of Colorado Health Sciences Center, Denver, CO 80262, Cardiovascular Pulmonary Research Laboratory, University of Colorado Health Sciences Center, Denver, CO 80262
APStracts 2:0113A, 1995.
High-altitude residence during pregnancy is associated with an increased incidence of preeclampsia. To determine whether uteroplacental blood flow was reduced and pelvic blood flow distribution altered before the onset of hypertension, we measured common iliac (CI), uterine (UA), and external iliac (EI) artery flow velocities (FV), indices of flow distribution, and blood volume (BV) at wk 12, 24 and 36 of pregnancy and 6 mos. postpartum in 23 normotensive, 7 preeclamptic, 5 transiently hypertensive and 3 chronically hypertensive residents of 3100 m. Normotensive women had a progressive increase in CIFV and UAFV, decrease in EIFV, redistribution of CIFV from the EI to the UA, and increase in BV with advancing pregnancy. Preeclamptic women attained maximal UAFV and redistribution of CIFV from the EI to the UA well before the onset of hypertension and, unlike normal women, showed no further increases near term. Plasma volume increment with pregnancy related to the fall in the EIFV to CIFV ratio. Transiently hypertensive women resembled normotensive subjects in the parameters measured, whereas chronically hypertensive subjects resembled preeclamptics. We concluded that preeclamptic vs. normal pregnant residents of high altitude had less redistribution of CI flow to the UA and no increase in UA blood flow near term. That these differences were present before the onset of hypertension supports the concept that preeclampsia is characterized by an incomplete vascular adjustment to pregnancy. 

Received 22 June 1994; accepted in final form 6 March 1995.
APS Manuscript Number A619-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 21 March 1995.