Assessment of fibrin(ogen) degradation products in preeclampsia using immunoblot, enzyme-linked immunosorbent assay, and latex-based agglutination. Plasma and serum from pregnant women with preeclampsia (N = 35) and normotensive pregnant (N = 71) and nonpregnant (N = 10) controls were screened for fibrin(ogen) degradation products (fibrinogen and cross-linked fibrin degradation products, and fibrin polymers) using three different assay systems (immunoblot, enzyme-linked immunosorbent assay [ELISA], and latex-bead agglutination assay). All tests showed statistically significant differences (P less than .05) between the preeclamptic patients and the other two groups (pregnant and nonpregnant women). The ELISA assay for total fibrin(ogen) degradation products was the most sensitive test, but was less specific than D-dimer latex. Eleven of the 35 preeclamptic women developed HELLP syndrome (hemolysis, elevated liver enzyme, and low platelet counts). Positive tests were as common in the 11 preeclamptic women who developed the syndrome as in the 24 who did not. These results suggest that fibrinolytic disorders are secondary pathophysiologic events in the course of preeclampsia, but further studies with a larger number of patients are needed. 