Abstract

OBJECTIVE: Pregnancies complicated by preeclampsia with a small for gestational age (SGA) neonate have poorer hemodynamic function compared to women with hypertensive disorders of pregnancy (HDP) and an appropriately grown neonate. Arterial stiffness is a recognised prognostic marker of cardiovascular disease in the general population. The aim of this study was to compare arterial stiffness in hypertensive pregnancies with and without SGA fetuses. METHODS: This was a prospective case control study of hypertensive and healthy normotensive pregnancies. Arterial stiffness, as assessed by pulse wave velocity (PWV) and aortic augmentation index (AIx), was recorded using a non-invasive device (Arteriograph®). Maternal and hemodynamic factors were adjusted for using linear regression analysis. Comparisons between groups were carried out using Mann-Whitney or Chi-Square (or Fisher's exact) test for categorical variables. RESULTS: Sixty-nine patients with HDP with SGA, 129 patients with HDP with a normally grown fetus and 220 healthy controls were included in the analysis. Maternal age, weight, height and heart rate were significantly associated with brachial and aortic AIx, whilst maternal weight, height, mean arterial pressure, heart rate and gestational age were significant predictors of aortic PWV. Both the HDP with SGA and HDP-only groups had significantly higher adjusted aortic AIx compared to controls (12.5% and 10.0% vs. 7.6%; both p<0.05) and were significantly different to each other (P=0.002). Adjusted PWV was significantly higher in the HDP-only group compared to the control group and the HDP with SGA group (7.7m/s vs. 7.1m/s and 7.1m/s, both p<0.001). Conversely, the unadjusted value was not significantly different between the two hypertensive groups (p=0.414). CONCLUSIONS: Pregnancies complicated by HDP with SGA or HDP-only have significantly higher aortic AIx compared to uncomplicated normotensive pregnancies. Aortic AIx was highest in those pregnancies complicated by preeclampsia with SGA, reflecting a progression in severity of arterial stiffness abnormality with a worsening clinical picture. These findings most likely reflect systemic reduced vascular compliance and increased systemic vascular resistance in HDP pregnancies. This article is protected by copyright. All rights reserved.