OBJECTIVE: To assess endothelial function at the level of skin microvasculature, using iontophoretic administration of acetylcholine (endothelium-dependent vasodilator) and sodium nitroprusside (endothelium-independent vasodilator), in women who recently had a preeclamptic pregnancy. METHODS: Microvascular skin reactivity was assessed by laser Doppler perfusion monitoring and iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) in 25 women with a history of early onset preeclampsia and 23 women with previous uncomplicated pregnancies, all of whom were between 3 and 11 months postpartum. RESULTS: Mean (±.standard error of the mean) ACh-mediated vasodilatation, expressed as a percentage increase in flux, was higher in women who recently had a preeclampsia than in controls (535 ±46%versus 314 ±29%, P < .001). In contrast, SNP-mediated vasodilatation was not significantly different (560±71%versus 483±69%, P = .4) in both groups. Linear regression analysis revealed that the difference in ACh-mediated vasodilatation was explained by preeclampsia (P = .004), whereas vascular risk factors such as maternal age, diastolic blood pressure, and family history of premature cardiovascular diseases had no significant effect. CONCLUSION: The increased ACh-mediated vasodilatation in the microcirculation of recently preeclamptic women indicates abnormal endothelial function. Furthermore, it may represent a compensatory response to an impaired vasodilatory response of the macrocirculation, thereby supporting the hypothesis of an underlying (micro)angiopathy. OBJECTIVE: To assess endothelial function at the level of skin microvasculature, using iontophoretic administration of acetylcholine (endothelium-dependent vasodilator) and sodium nitroprusside (endothelium-independent vasodilator), in women who had had a preeclamptic pregnancy. METHODS: Microvascular skin reactivity was assessed by laser Doppler perfusion monitoring and iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) in 25 women with a history of early onset preeclampsia and 23 women with previous uncomplicated pregnancies, all of whom were between 3 and 11 months postpartum. RESULTS: Mean (±. Standard error of the mean) ACh-mediated vasodilatation, expressed as a percentage increase in flux, was higher in women who had had a preeclampsia than in controls (535 ± 46% versus 314 ± 29%, P <.001) . In contrast, SNP-mediated vasodilatation was not significantly different (560 ± 71% versus 483 ± 69%, P = .4) in both groups. Linear regression analysis revealed that the difference in ACh-mediated vasodilatation was explained by preeclampsia (P = .004), whereas vascular risk factors such as maternal age, diastolic blood pressure, and family history of premature cardiovascular diseases had no significant effect. CONCLUSION: The increased ACh-mediated vasodilatation in the microcirculation of recently preeclampory women in response to the macrocirculation, thereby supporting the hypothesis of an underlying (micro) angiopathy.