Vascular mechanical properties and endothelial function in pre‐eclampsia with special reference to bilateral uterine artery notch

Abstract

To assess whether women with pre-eclampsia (PE) have different properties of the blood vessel wall compared to healthy pregnant controls. Further, to evaluate endothelial function and vascular mechanical properties in women with PE with special regard to its association with bilateral uterine artery notch and placental histopathology. Some 57 Caucasian pregnant women: 23 with uncomplicated pregnancies and normal uterine artery Doppler, and 34 with PE, the PE group comprising 2 subgroups according to the presence (n=20) or absence (n=14) of bilateral uterine artery notches. Ultrasonic echo-tracking assessed the elastic properties of the common carotid artery, abdominal aorta and popliteal artery. Flow-mediated dilatation (FMD) of the brachial artery was measured by ultrasonography. Histopathological examination of the placenta was carried out in 46 pregnancies: 18 uncomplicated pregnancies, 15 with PE with bilateral notch, and 13 with PE without bilateral notch. There were no significant differences in carotid, aortic or popliteal vessel wall stiffness either between women with PE and controls or within the PE group. FMD was significantly lower in women with PE than in controls (p=0.03). The lowest FMD was observed in pre-eclamptic women with bilateral uterine artery notches 9.5% (SD: 5.3) compared to 11.6% (SD: 5.4) in pre-eclamptic women without bilateral uterine artery notch, and 13.4% (SD: 4.0) in controls (p=0.01). Bilateral uterine artery notching was significantly associated with a lower FMD (OR: 0.87; 95% CI: 0.77-0.98). There were significantly more placentas with high ischaemic score in the bilateral notch group than in the group with PE and normal circulation. There were no differences in vessel wall stiffness between women with PE and healthy controls. Women with PE showed signs of endothelial dysfunction, significantly more pronounced in women with bilateral uterine artery notch. Bilateral uterine artery notch was associated with ischaemic pathology of the placenta. Notwithstanding, a significant number of placentas in the PE group failed to show noteworthy ischaemic or other morphological changes that could explain the role of the placenta in the development of PE.