Hormonal Contraception and the Risk of Pulmonary Embolism in Women of Reproductive Age: A Narrative Review with Clinical Perspectives

Pulmonary Embolism (PE) remains a relevant source of morbidity in women of reproductive age, although it is often unrecognized. Hormonal contraception is a well-established acquired risk factor for PE because of its association with venous thromboembolic events; however, it has varying effects on different patients based on their risk profiles and the forms of hormonal contraception they are receiving. This narrative review summarizes the evidence regarding hormonal contraception and its relationship to PE, with an emphasis on the biological mechanisms involved in this process, the differences in risk associated with different types of hormonal contraceptives, and the clinical implications (as well as various other factors) that the clinician may need to consider when counseling a patient regarding hormonal contraceptives (i.e., potential benefits versus risks). Available data consistently show that estrogen-containing combined hormonal contraceptives increase the risk of venous thromboembolism compared with nonuse, although the absolute risk remains low in otherwise healthy young women. The degree of excess risk appears to vary according to estrogen dose, progestin type, and route of administration. Thrombosis rates are generally lower with the levonorgestrel-containing estrogen-containing contraceptives; however, many non-oral combined contraceptive methods and some third- and fourth-generation hormone contraceptives did not appear to be as favorable based on observational studies. In addition to the effect of hormones on thromboembolic (TE) events, other risk factors such as obesity, smoking, thrombophilia, prior venous thromboembolism and transient provoking factors such as surgery or prolonged immobilization also affect the overall clinical significance of hormone use. By contrast, most progestin-only methods appear to have little or no meaningful effect on venous thromboembolism risk, making them important alternatives for women in whom estrogen is not appropriate. Taken together, current evidence supports an individualized approach to contraceptive choice, based on careful assessment of baseline thrombotic risk, thorough clinical history taking before prescription, and reassessment of contraceptive options after a thromboembolic event.