Noninvasive Assessment of Flow-Mediated Vasodilation With 30-MHz Transducer in Pregnant Women

To the Editor: Cockell and Poston (April 1997)1 reported that flow-mediated vasodilation is enhanced in pregnant women but reduced in preeclampsia. They assessed the vasodilation using biopsies of small arteries. Therefore, their assessment was not in vivo but in vitro study. We assessed flow-mediated vasodilation in pregnant women noninvasively. Noninvasive assessment of flow-mediated vasodilation in nonpregnant subjects was first reported by Celermajer et al,2 who measured the brachial artery with high-resolution ultrasound (7.5-MHz transducer). We previously reported that with a 30-MHz transducer it is possible to detect endothelial dysfunction more accurately by measuring the radial artery.3 We examined 60 Japanese women including 20 nonpregnant normotensive healthy women (28.7±5.0 years old), 18 normal pregnant women (31.3±5.0 years old, 35.8±3.1 weeks of pregnancy), and 22 pregnant women with preeclampsia (29.8±3.8 years old, 36.0±3.3 weeks of pregnancy). The diagnosis of preeclampsia was made according to the criteria of the Committee on Terminology of the American Collage of Obstetricians and Gynecologists.4 All 60 subjects were …