Objective: Changes in hemostatic system were evaluated in healthy pregnant women. Methods: Blood was sampled in the 1st, 2nd and 3rd trimesters of gestation, during delivery and 3 days postpartum and plasma factors were measured using commercial tests. Results: Thrombin-antithrombin III complexes, fibrinopeptide A and D-dimer were higher during pregnancy. The endothelial cell markers, fibronectin and tissue factor, remained within the normal reference values in the healthy nonpregnant population. This result suggests no endothelial injury and shows no activation of extrinsic coagulation pathway during pregnancy. The balance coagulation/fibrinolysy is maintained during pregnancy and delivery, as shown by the ratio fibrinopeptide A/D-dimer, however, a tendency towards coagulation process is developed in the early puerperium.