Preeclampsia is not associated with excess fetal clotting.

Paired maternal and umbilical vein blood samples were obtained from 15 women and the plasma antithrombin III activity and fibrinopeptide A concentration measured. Women with preeclampsia had significantly lower antithrombin III activities and higher fibrinopeptide A concentrations (P less than .05) than normals. However, there were no significant differences between the two groups of fetuses. Thus, thrombin generation was not increased in the fetuses delivered from preeclamptic women.