From the Research
For patients with antithrombin (AT) deficiency, progestin-only contraceptives are the best oral birth control option, as they avoid the thrombogenic effects of estrogen while providing effective contraception. Specifically, desogestrel (Cerazette, 75 mcg daily), norethindrone (Micronor, 0.35 mg daily), or norgestrel (Ovrette, 0.075 mg daily) are recommended, as stated in the most recent study 1. These progestin-only pills should be taken at the same time each day without breaks between packs. AT deficiency significantly increases thrombosis risk, and combined estrogen-progestin contraceptives would further elevate this risk.
Some key points to consider:
- Progestin-only methods are generally considered safe for women at high risk for thrombosis, including those with AT deficiency 2.
- Alternative non-oral options include the levonorgestrel IUD (Mirena, Kyleena, or Liletta), etonogestrel implant (Nexplanon), or depot medroxyprogesterone acetate injections (DMPA, 150 mg every 3 months) 1.
- Patients should be counseled that progestin-only pills have a slightly higher typical-use failure rate than combined pills and require strict adherence to timing, as well as potential irregular bleeding patterns, especially in the first few months of use 3.
- The risk of thrombosis associated with hormonal contraceptives is influenced by the type of progestin and estrogen dose, with newer COCs containing desogestrel, gestodene, or drospirenone having a higher risk than older COCs with levonorgestrel or norethisterone 4, 5.
Overall, the best approach for managing contraception in patients with AT deficiency is to use progestin-only methods, which minimize the risk of thrombosis while providing effective contraception, as supported by the most recent and highest quality study 1.