 NESTED STUDY 1: Effect of tranexamic acid on coagulation in a sample of 400 participants in the WOMAN trial ETAC. This aims to evaluate the effect of TXA on markers of coagulation in a sample of WOMAN trial participants. Standard coagulation parameters platelets, fibrinogen, PT and aPTT time and D-dimer and ROTEM parameters measured after in vitro activation with tissue factor EXTEM and inhibition with aprotinin APTEM will be determined maximum lysis, maximum strength Maximal Clot Firmness MCF, time from start to when the waveform reaches 2mm above baseline Clotting Time CT, time from 2mm above baseline to 20mm above baseline Clot Formation Time CFT, time to lysis CLT 10 difference from MCF, time to Maximum strength MCF-t, Clot elasticity MCE. 