The influence of the third and fourth generation of combined oral contraceptives on hematological and hemostasis parameters.

Abstract

Background/Objectives: Combined oral contraceptives (COC) represent an effective form of fertility control, with numerous potential side effects. The aim was to monitor the difference in hematological and hemostatic parameters in users and nonusers of oral contraceptives. Methods: A descriptive study included 121 subjects, classified as 72 oral contraceptive users and 49 nonusers. Participants were recruited by randomization from the Institute for Student Health Care in Novi Sad. Results: There was no difference in age and body mass index between the groups. The frequency of smoking was higher in the nonusers compared to users (36% vs. 19%; χ ²=0.039). No significant difference in hematological parameters when comparing the groups was noted. Activated partial thromboplastin time (aPTT) and prothrombin time (PT) were significantly shorter in the users compared to nonusers (24.69 ± 1.83 s vs. 25.78 ± 2.85 s; p = 0.011 and 9.72 ± 2.16 s vs. 10.50 ± 1.93 s vs. p = 0.045, respectively). Significant differences in area under the curve (AUC) for endogenous thrombin potential (ETP) and the time required to reach the maximum thrombin level (ETP-_tmax) were noticed when comparing oral contraceptive users and the control group (111.40 ± 28.14 % vs. 93.32 ± 17.03 %; p = 0.02, and 69.85 ± 11.15 vs. 80.78 ± 14.87 s, p = 0.02, respectively). There was no difference in fibrinogen and D-dimer concentrations, while antithrombin and von Willebrand factor were lower in the control group, without statistical significance. Conclusion: The use of oral contraceptives of the third and fourth generation leads to changes in the hemostasis functionality in terms of the shortening of aPTT and PT, and an increase in ETP, thus potentially enabling the identification of women with the increased venous thrombosis risk.