VPB1429 - Association between a first-trimester retrochorionic hematoma and plasminogen activity level

Background: Retrochorionic hematomas are the most common cause of vaginal bleeding in the first trimester of pregnancy. Disturbances in the blood coagulation system could probably lead to the appearance of retrochorionic hematomas

Aims: To assess the association of a first-trimester retrochorionic hematoma with plasminogen activity(%PLG) and level of IgG and IgM binding to plasminogen in system circulation.

Methods: The study included 73 consecutive consenting pregnant women (18-40 years old, 5-13 weeks of gestation):16 patients had retrochorionic hematoma, and 57 women were with uncomplicated pregnancy. Tests were performed in thrombocyte free plasma. We analyzed such characteristics as prothrombin time(PT), activated partial thromboplastin time(aPTT), thrombin time(TT), fibrinogen(FB) and %PLG. The concentration of soluble fibrin-monomer complexes(SFMCs) was determined by ortho-phenanthroline test. The content of D-dimer, plasminogen, levels of IgG and IgM binding plasminogen were revealed by ELISA. Statistical analysis was performed using Spearman's rank correlations(r), ROC analysis, the nonparametric Mann-Whitney test with a critical value of p< 0.05. Data are presented as median with interquartile range(Me;Q1-Q3).

Results: We revealed a weak positive correlation(r=0.29) in healthy women between aPTT(30.6s;29.1-33.3) and IgM-Plg(89.4u/ml;67.2-119.6), but patients with hematomas had a stronger correlation (r=0.51) between aPTT(32.8s;30.6-36.0) and IgM-Plg(100.6u/ml;76.5-140.3). Patients with hematomas was a positive correlation (r=0.55) between TT(19.0s;18.1-20.8) and IgM-Plg. In the control group showed a weak negative correlation (r=-0.27) between gestational age and PT(11.5s;11.2-12.0). There was a weak positive correlation with FB(3.3 g/L;2.8-3.9)(r=0.33) and %PLG(116.5%;91.8-143.4)(r=0.38). Patients with hematomas had higher PT(12.5s;12.1-12.9)(p=0.0006), SFMCs(4.0mg/L;3.0-5.3) and lower %PLG(82.5%;66.7-91.0)(p=0.0007), than healthy women SFMCs(3.0mg/L; 3.0-4.0)(p=0.004). ROC analysis was applied to estimate the sensitivity (SN) and specificity (SP) of %PLG to differ women with retrochorionic hematoma from healthy pregnant women (SN=100%;SP=68.4%,AUC=0.85). The ratio of %PLG/IgM-Plg had a high significance (SN=75%;SP=88%;AUC=0.82).

Conclusion(s): Plasminogen activity and %PLG/IgM-Plg ratio could be used as potential markers to revealed hematoma, what is important, especially in the early pregnancy.