Does endothelial cell activation occur with intrauterine growth restriction?

It is possible that in fetal growth restriction without pre-eclampsia endothelial cell activation does not occur. This might be either because there is no release of 'factor X' or because of maternal resistance to its effects. To test this hypothesis, we took blood samples from 26 women with pre-eclampsia (without fetal growth restriction), 13 women with fetal growth restriction (without pre-eclampsia) and 24 normal pregnant controls, and measured the circulating levels of three markers of endothelial cell activation (soluble VCAM, ICAM and E-selectin) and three cytokines [tumour necrosis factor-a (TNF-alpha), interleukin-6 (IL-6) and -8 (IL-8)]. The levels of the markers of endothelial cell activation were raised in both pre-eclampsia and fetal growth restriction pregnancies compared with controls; however, the levels of TNF-alpha, IL-6 and IL-8 were significantly raised in pregnancies complicated by pre-eclampsia, but not in fetal growth restriction, compared with controls. These data show that endothelial cell activation is common to both pre-eclampsia and fetal growth restriction, but that the circulating levels of cytokines are elevated only in pre-eclampsia. Thus, it seems likely that endothelial cell activation is a consequence of a failure of trophoblast invasion and that a further step is required, possibly involving cytokine release, for the expression of the full clinical picture of pre-eclampsia.