Hormone Replacement Therapy and Thromboembolic Risk: Review of Current Evidence
Hormone Replacement Therapy (HRT) is widely used to relieve menopausal symptoms and improve quality of life. However, its impact on thromboembolic risk has been a constant concern. In this article, we review the latest evidence on the relationship between HRT and venous thromboembolism (VTE), considering different routes of administration and types of hormones.
Hormone Replacement Therapy (HRT) is widely used to relieve menopausal symptoms and improve quality of life. However, its impact on thromboembolic risk has been a constant concern. In this article, we review the latest evidence on the relationship between HRT and venous thromboembolism (VTE), considering different routes of administration and types of hormones.
HRT and the Risk of Venous Thromboembolism
Studies indicate that oral HRT is associated with a significant increase in the risk of VTE, particularly in the first few months of use. The literature points to a relative risk (RR) of 2 to 4 for users of combined oral HRT compared to non-users.
On the other hand, transdermal HRT presents a lower risk. Meta-analyses show that there is no statistically significant increase in risk with this route of administration (OR 0.97). Additionally, transdermal formulations containing only estrogen have an even lower relative risk (OR 0.95).
Influence of Progestogens on VTE Risk
The type of progestogen used in HRT also impacts the thrombotic risk. Micronized progesterone and dydrogesterone are associated with lower risks, whereas medroxyprogesterone acetate may increase the risk of VTE.
The combination of transdermal estrogen with micronized progesterone is considered a safer option for women with a predisposition to thrombotic events.
HRT in Women with Thrombophilia
The presence of hereditary thrombophilias, such as Factor V Leiden mutation and prothrombin mutation, necessitates careful evaluation before prescribing HRT.
Studies suggest that oral HRT may exacerbate thrombotic risk in individuals with these conditions, especially when additional factors, such as obesity or immobility, are present.
Clinical Considerations and Conclusion
While many healthy women can safely use HRT, those with a history of VTE or thrombophilia require a personalized approach. Transdermal HRT, combined with lower-risk progestogens, is generally preferable in these high-risk populations.
Doctors should conduct detailed evaluations of the thrombotic history before prescribing HRT. In more complex cases, collaboration with hematology specialists may be essential for safe and effective management of hormonal therapy.
