Which birth control method is safest for a woman with a history of deep vein thrombosis?

The levonorgestrel-releasing IUD is the safest birth control method for a woman with a history of deep vein thrombosis (DVT) due to its hormonal profile and the way it functions. Unlike the other options, the levonorgestrel IUD primarily releases progestin locally within the uterus, which reduces the overall systemic exposure to hormones. This localized effect decreases the risk of thromboembolic events, which is especially important for women with a history of DVT.

In contrast, combined hormonal methods such as the vaginal ring, transdermal patch, and combined oral contraceptive pill can increase the risk of thrombosis because they contain both estrogen and progestin. Estrogen is known to elevate the risk of clot formation, which is a significant concern for women who have previously experienced DVT. Therefore, these methods could potentially exacerbate a woman's condition and lead to further complications.

The levonorgestrel IUD, being a hormonal method that does not involve estrogen, provides effective contraception while minimizing the risk of adverse events related to venous thromboembolism for women who have had a history of DVT.