Thrombotic risks of oral contraceptives.

PURPOSE OF REVIEW: To inform about the risk of venous thromboembolism (VTE) of different hormonal contraceptives in different patient groups.

RECENT FINDINGS: Combined oral contraceptives (COCs) differ significantly regarding VTE risk depending on amount of estrogen and type of progestogen: COCs containing desogestrol, gestoden or drospirenone in combination with ethinylestradiol (so called third-generation or fourth-generation COCs) are associated with a higher VTE risk than COCs with ethinylestradiol and levonorgestrel or norethisterone (so called second-generation COCs). The VTE risk for transdermal COCs like vaginal ring (NuvaRing) or patch (Evra) is as high as for COCs of third or fourth generation. Progestogen-only contraceptive methods do not increase VTE risk significantly. New kinds of COC without ethinylestradiol but with estradiol valerat or estradiol showed a much lower degree of coagulation activation than 'classical' COC containing ethinylestradiol.

SUMMARY: Second-generation COCs should be the first choice when prescribing hormonal contraception.In patients with a history of VTE and/or a known thrombophilic defect, COCs are contraindicated, but progestogen-only contraceptives can be safely used in this patient group. Whether newer COCs with estradiol valerate or estradiol have a lower VTE risk remains to be elucidated.