The effect of low-dose estroprogestinic preparations on prothrombin complex factors: no significant increase after an 8-month trial.

The behavior of the prothrombin complex factors in 16 healthy women during low-dose estroprogestinic treatment (laevonorgestrel 0.15 mg and ethynilestradiol 0.30 mg) at basal conditions and during 8 months of therapy has been investigated. We found a statistically significant decrease of the PTT (Partial Thromboplastin Time). The prothrombin time, on the other hand, became slightly decreased, but not to a statistically significant extent. Among the prothrombin time derived tests for evaluating the prothrombin complex only the PP test (Prothrombin Proconvertin test) was significantly shortened. Of the coagulation factors (factors II, VII and X) only a modest, but not statistically significant, increase in Factor VII and Factor X was noted. We conclude that, during the 8 month observation period, prothrombin complex factors are not altered substantially.