Resistance to activated
protein C (APC) is a condition that leads to a hypercoagulative state with an increased risk for
venous thrombosis. The aim of this study was to test the functionality of the
protein C system in normal and complicated pregnancies and
APC resistance. A total of 131 patients were tested, including pregnant women with normal and complicated pregnancies at different periods, e.g. from weeks 1 to 20, 21 to 30 and 31 to 38 of gestation. The following
hemostatic parameters were determined:
protein S,
protein C,
protein C Global and
protein C APC sensitivity. Commercial "Behring" tests were used to determine the parameters of hemostasis. The values for
protein C activity were within normal limits.
Protein S values were below the lower limits. Significantly lower PC-NR (
protein C normalized ratio) and APC-NR (activated
protein C normalized ratio) values were found in all three of the gestation periods in pregnant women with a history of repeated
miscarriages and
hypertension in relation to pregnant women with normal pregnancies. In order to assess the diagnostic accuracy of investigated
hemostatic parameters as markers of prethrombotic changes in pregnant women, the obtained values of investigated
hemostatic parameters were evaluated by ROC analysis. PC-NR and APC-NR showed satisfactory diagnostic accuracy as markers of prethrombotic changes in pregnant women: more precisely, they were found to be good indicators of resistance to activated
protein C in pregnancy.