OP18.01: Assessment of Fetal Brain Vascularisation in Fetuses Affected by Late Onset Fetal Growth Restriction Using Three‐dimensional Power Doppler Angiography

function in pregnancy. In this study, we made a comprehensive evaluation of in vivo vascular function (including flow-mediated dilatation (FMD), peripheral arterial tonometry (PAT), and arterial stiffness) in pre-eclamptic patients and compared them to normal pregnancies. In addition, we assessed the evolution of vascular function during normal pregnancy and the trend in vascular function after pre-eclamptic pregnancies. Methods: 14 patients with pre-eclampsia (PE) and 14 healthy pregnant controls were included. Endothelial function was determined by FMD and PAT, arterial stiffness by carotid-femoral pulse wave velocity (cfPWV) and augmentation index (AIx). Results: The reactive hyperemia index (RHI) assessed using PAT is decreased at the third trimester in comparison to the first trimester in an uncomplicated pregnancy (1.5±0.3 vs 2.3±0.6, p=0.001). Arterial stiffness is significantly higher in PE versus normal pregnancy (cfPWV 7.7±0.9 vs 6.0±0.8; AIx 23±8.8 vs 9±9.8; p<0.001). Endothelial function obtained by FMD is deteriorated in PE versus normal pregnancy (4.8±3.1 vs 8.5±4.1; p=0.015), while endothelial function assessment by PAT is improved in PE versus normal pregnancy (2.1±0.4 vs 1.5±0.3; p=0.001). Both arterial stiffness (cfPWV 7.0±0.6 vs 7.9±0.9; p=0.009, AIx 6.9±11.0 vs 26.3±7.8; p<0.0001) and endothelial function obtained by FMD (9.0±3.9 vs 5.2±3.7; p=0.02) are ameliorated six months after PE. Conclusions: Flow mediated dilation and peripheral arterial tonometry are disturbed in PE, yet are improved six months post-partum. Endothelial function assessed by FMD and PAT show distinct results. This may indicate that measurements with FMD and PAT reflect different aspects of endothelial function and that PAT should not be used as a substitute for FMD as a measure of endothelial function in pregnancy.