Effects of red blood cells on the coagulation of blood in normal and preeclamptic pregnancies,

Objective: The objective of this study was to determine the cellular effects of whole blood, especially of red blood cells, on the hypercoagulability of blood from patients with preeclampsia. Study Design: The time elapsed between mixing and the onset of coagulation was measured by means of a highly sensitive rheometer for whole blood, platelet-rich plasma (in which red blood cells had been removed from whole blood), and platelet-free plasma from 3 groups of subjects: 25 nonpregnant women, 25 women with normal pregnancies, and 10 patients with preeclampsia. Results: Time to coagulation for whole blood from patients with preeclampsia was significantly shorter than that for whole blood from women with normal pregnancies. However, there was no significant difference in time to coagulation for platelet-rich plasma between women with preeclampsia and those with normal pregnancies. Conclusion: Hypercoagulability of blood in preeclampsia appears to be strongly related to red blood cell alterations.(Am J Obstet Gynecol 1999;180:402-5.)