New observations on procoagulant properties of amniotic fluid: Microparticles (MPs) and tissue factor-bearing MPs (MPs-TF), comparison with maternal blood plasma

IntroductionMicroparticles (MPs) are submicron fragments of the cell membrane affecting many biological processes, e.g. coagulation. The aim of the study was to determine (i) MPs and (ii) tissue factor bearing MPs (MPs-TF) in the amniotic fluid and in blood plasma of parturient women, as well as to assess (iii) TF and TFPI.Material and methodsThe study group consisted of 38 women laboring at term, whereas the control group included 20 non-pregnant women. ELISA method was used to evaluate MPs, MPs-TF, TF and TFPI.ResultsThe levels of MPs and MPs-TF were significantly higher in the amniotic fluid than in blood plasma of parturient women: the level of MPs was 41.08 times higher (medians: 246.48 nM PS vs. 6.00 nM PS, respectively, p < 0.001), and the level of MPs-TF was 18.59 times higher (medians: 90.16 pg/ml vs. 4.85 pg/ml, respectively) (p < 0.001).Conclusions1. Microparticles (MPs) and tissue factor-bearing MPs (MPs-TF) are constituent components of amniotic fluid. 2. It is reasonable to assume that these components together with tissue factor (TF) and its inhibitor (TFPI) can participate in life-threatening coagulation disturbances in amniotic fluid embolism, and to take into consideration their impact on fetal development.