Spiral artery blood volume in normal pregnancies and those compromised by pre‐eclampsia

Abstract The aim of this work was to use intravoxel incoherent motion (IVIM) to provide a non‐invasive in vivo assessment of the function of the maternal spiral arteries that feed the placenta in normal pregnancy and in pre‐eclampsia. Eleven normal pregnant women were scanned at 16, 22, 29 and 35 weeks gestation in a longitudinal study. Nine normal pregnant women and six women with pre‐eclampsia were scanned in a cross‐sectional study, within 10 days of delivery. The MRI IVIM technique was used to measure the moving blood fraction (f%) at the basal plate. There was no evidence that f% changed with gestational age (P = 0.84), but considering the cross‐sectional groups, f% in women with pre‐eclampsia was reduced compared with normal pregnancy (mean ± SD: 36 ± 5% and 27 ± 5%; P < 0.005). In conclusion, pregnancies complicated by pre‐eclampsia exhibit a reduced fraction of moving blood within the region of the spiral arteries. IVIM performed in the mid‐trimester may provide an early means of predicting those pregnancies with an increased likelihood of being complicated by pre‐eclampsia. Copyright © 2007 John Wiley & Sons, Ltd.