Comparative study of the effects of combined oral contraceptives in hemostatic variables: an observational preliminary study.

Thrombotic risk is associated with the estrogen dose and type of progestin in combined oral contraceptives. Studies published since 1990 showed that third-generation progestins have larger risk to contribute to thrombosis development than the second-generation. However there are conflicts in the literature regarding the thrombotic risk associated to the drospirenone progestin. So this study aimed to evaluate the effects of 3 formulations of contraceptives containing ethinylestradiol (EE) (20 and 30 mug) combined with drospirenone versus levonorgestrel combined with EE (30 mug) in hemostatic parameters.This cross-sectional study included 70 healthy women between 18 and 30 years BMI 19 to 30 kg/m not pregnant non-smokers and users or non-users (control) of contraceptives for a minimum period of 6 months. The following parameters were assessed: prothrombin time (PT) Factor VII activated partial thromboplastin time (aPTT) Factor XII fibrinogen Factor 1 + 2 Protein C Protein S antithrombin D-dimers and plasminogen activator inhibitor-1.Significant alterations were found in PT aPTT fibrinogen D-dimers and protein S all favoring a state of hypercoagulation for contraceptive containing DRSP/20EE. Both contraceptives containing DRSP/30EE and LNG/30EE promoted changes that favor the hypercoagulability in the coagulant variable PT and in the anticoagulant variables Protein S and Protein C respectively.We suggest that the progestin drospirenone can contribute to an inadequate balance among procoagulant anticoagulant and fibrinolytic factors since that the contraceptive containing the lowest dose of estrogen and drospirenone (DRSP/20EE) caused a higher number of hemostatic changes.