Stroke and myocardial infarction with contemporary hormonal contraception: real-world, nationwide, prospective cohort study.

Summary

In a nationwide cohort of 2,025,691 Danish women, combined oral contraceptives doubled the risk of ischemic stroke and MI, while progestin-only pills modestly increased risk. Levonorgestrel-releasing IUDs showed no increased arterial risk. Absolute event rates were low but clinically relevant for risk–benefit counseling.

Key Findings

• Combined oral contraception doubled adjusted rates of ischemic stroke and myocardial infarction versus non-use (aIRR ≈2.0).
• Progestin-only pills increased risk modestly (stroke aIRR 1.6; MI aIRR 1.5).
• Levonorgestrel-releasing intrauterine devices showed no increased risk (stroke aIRR 1.1; MI aIRR 1.1).

Clinical Implications

Use levonorgestrel IUDs when minimizing arterial risk is paramount; discuss small but meaningful arterial risks with combined oral or progestin-only pills, particularly in patients with vascular risk factors.

Limitations

• Observational design with potential residual confounding (e.g., smoking, blood pressure).
• Generalizability may vary outside Denmark; absolute risks remain low.

Future Directions

Evaluate individualized contraceptive risk calculators integrating vascular risk factors; assess mechanisms and differential progestins’ arterial effects; extend to diverse populations.