Impaired vasoconstriction in pregnancy-induced hypertension assessed usingDoppler fluximetry

Objective: To determine whether there is a difference in peripheral vascula r reactivity between normal women and those with pregnancy-induced hyperten sion. Methods: Capillary blood flow (flux) was recorded in the skin over the ankl e in 26 pregnant women with pregnancy-induced hypertension at term. Twelve of these women had proteinuria, and 14 were nonproteinuric. Leg lowering wa s used to activate the venoarteriolar reflex, and the resultant change in f lux, expressed as a percentage change from the baseline, was used as an ind ex of vascular reactivity. The results were compared with those of a contro l group comprising 23 matched normotensive women. The study was repeated on all of the women after delivery. Results: Women with hypertension showed a median (range) increase in flux o f +24.4% (-15.5% to +151.1%), significantly different from controls: -39.3% (-80.9% to -4.3%, P < .001). This difference persisted regardless of the p resence or absence of proteinuria. Responses in women with pregnancy-induce d hypertension were significantly different after delivery (median -60.7%; range -158.5% to -19.5%, P < .001) when compared with predelivery responses . Similar changes as a result of delivery were seen in women with proteinur ic (medians +25.9% and -57.9%, P < .002) and nonproteinuric (medians +7.8% and -62.8%, P < .001) hypertension but not in controls. Postdelivery respon ses in women with hypertension were no different from those of controls. Conclusion: Women with pregnancy-induced hypertension have abnormal cutaneo us vascular reactivity that returns to normal after delivery. (C) 2000 by T he American College of Obstetricians and Gynecologists.