What type of contraceptive method might be contraindicated for women who smoke?

Combination oral contraceptives are indeed contraindicated for women who smoke, particularly those who are over the age of 35. This is primarily due to the increased risk of thromboembolic events, such as deep vein thrombosis (DVT) and pulmonary embolism, associated with both smoking and the use of estrogen-containing contraceptives. Estrogens in these oral contraceptives can elevate the risk of blood clots, and when combined with smoking — which itself increases clotting risk — this combination poses a serious health threat.

In contrast, contraceptive implants, barrier methods, and intrauterine devices (IUDs) do not carry the same thromboembolic risk. These methods either do not contain estrogen or do not influence the coagulation pathways significantly as combination oral contraceptives do. Therefore, while women who smoke are strongly advised to avoid combination oral contraceptives, they can choose alternative methods without facing the same heightened risk of complications.