Uteroplacental blood flow and placental vascular endothelial growth factorin normotensive and pre-eclamptic pregnancy

Objective To determine whether placental vascular endothelial growth factor (VEGF) is increased in pre-eclampsia. Design Prospective cohort study. Setting Royal Prince Alfred Hospital, Sydney, Australia. Sample Eleven normotensive women and eight women with pre-eclampsia matched for age and gestation. Methods Uterine artery Doppler ultrasound flow velocity profiles were recor ded in the third trimester and resistance index calculated as (V-s-V-d)/V-s (V-s = peak systolic flow velocity, V-d = end diastolic flow velocity). Pl acental tis sue at delivery was examined for VEGF distribution with avidin- biotin-peroxidase immunohistochemistry. Results Uterine resistance index [median (range)] was significantly increas ed in pre-eclamptic women (normotensive: 0.42 (0.36-0.51); pre-eclampsia: 0 .59 (0.40-0.75); P = 0.005). Notching of the uterine artery waveform, consi stent with a high resistance circulation, was evident in early diastole in five women with pre-eclampsia but only one normotensive woman (P = 0.013). Placental VEGF was increased in women with pre-eclampsia in the decidual tr ophoblast (normotensive: 34% (4-59) cells stained for VEGF; pre-eclampsia: 58% (15-95); P = 0.033) and in the villous syncytiotrophoblast (normotensiv e: VEGF count 1.4 arbitrary units (1.1-2.1); pre-eclampsia: 1.8 arbitrary u nits (1.4-2.2); P = 0.041). Analysis indicated that uterine artery resistan ce index was directly correlated with placental VEGF staining, mean arteria l pressure and birthweight. Conclusions Abnormal uterine artery Doppler ultrasound flow velocity profil es in pre-eclampsia indicate increased uteroplacental resistance. The assoc iated increase in placental VEGF may represent a compensatory mechanism att empting to restore blood flow towards normal.