VEGF Expression in the Placenta from Pregnancies Complicated by Hypertensive Disorders

Objective: To determine the expression of VEGF in the placental tissue from pregnancies complicated by hypertension disorders of different clinical severity.

Design: Prospective cohort study.

Setting: Polyclinic of Careggi, University of Florence, Italy.

Sample: Placentas from women with gestational hypertension (n= 20), pre-eclampsia (n= 20) and pre-eclampsia with HELLP syndrome (n= 20) and from normotensive women (n= 20), as control group (gestational age comprised between 35 and 38 weeks).

Methods: An immunohistochemical technique and a quantitative analysis to measure mRNA levels (RT-PCR) were employed.

Main Outcome Measures: Intensity of immunoreactivity and mRNA levels in the placental components. Differences between the data.

Results: VEGF immunoreactivity was observable in all the placental components in the gestational hypertension cases as in the control ones. In the cases with pre-eclampsia and pre-eclampsia with HELLP syndrome, some placental components were not immunoreactive. However, the VEGF positive components of all the pathological groups showed a higher intensity of reactivity with respect to that of the control group. The levels of VEGF mRNA were higher in the gestational hypertension cases and lower in the cases of pre-eclampsia with HELLP syndrome with respect to the control ones; in the cases of pre-eclampsia, the levels were the same as the control ones.

Conclusion: The different expression of VEGF in the placenta of the pathological cases is probably related to haemodynamic changes that take place in these disorders, in order to attempt restoration of a normal uteroplacental flow.