Pregnancy induces several haemostatic perturbations. Some authors described possible acquired activated protein C resistance (APCR) during normal pregnancy. We wanted to test this possibility and to evaluate if this acquired APCR might contribute to the known increased tendency to thrombosis associated with pregnancy. To answer the first hypothesis, we tested APCR with standard and with modified (5) APTT assays; to explore the second one, we chose to test some hypercoagulability and hyperfibrinolysis markers, i.e. fibrinopeptide A (FPA), Fragment 1+2 (F1+2) and D-dimers, and to correlate them with APC-ratio.