Traitement hormonal de la ménopause : un risque accru de thrombose
Par Mme Aude Rambaud
(Saint-Germain-en-Laye)
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Date de publication : 15 octobre 2026 Temps de lecture: 2 min
Comparativement à l’absence de traitement hormonal, un traitement hormonal de la ménopause est associé à une augmentation du risque thromboembolique, notamment veineux, indépendamment de la posologie et de la durée du traitement. C’est ce qu’indique une étude parue dans le BMJ.
Une équipe a étudié les associations entre l’utilisation actuelle d’un traitement hormonal de la ménopause et la survenue d’une thromboembolie veineuse, d’un accident vasculaire cérébral ischémique et d’un infarctus du myocarde à partir de registres nationaux de santé danois.
Elle a inclus 9807 femmes atteintes d’une thromboembolie veineuse, 18.460 femmes ayant subi un accident vasculaire cérébral ischémique et 11.974 femmes ayant subi un infarctus du myocarde au sein d’une cohorte de femmes âgées de 50 à 69 ans alors qu’elles ne présentaient aucun antécédent de thrombose.
Les cas ont été appariés par année de naissance à des femmes sans maladie thrombotique.
Comparativement à l’absence de traitement, l’utilisation actuelle d’un traitement œstrogénique oral (seul ou combiné à un progestatif) était associée à des taux accrus de thromboembolie veineuse (RR 1,5 à 1,8), d’accident vasculaire cérébral ischémique (1,2 à 1,4) et d’infarctus du myocarde (1,1 à 1,3).
Le nombre de patientes à traiter pour observer un effet indésirable après un an d’utilisation était respectivement 1055 (791 à 1266), 1642 (1232 à 2463) et 3846 (2564 à 7692).
L’administration orale d’œstradiol à des doses supérieures à 1 mg/jour pendant plus d’un an était associée à une augmentation du risque d’accident vasculaire cérébral ischémique et d’infarctus du myocarde, ce risque augmentant avec la durée du traitement (RR d’AVC : 1,8 ; 1,4 à 2,2 ; RR d’infarctus du myocarde : 1,8 ; 1,4 à 2,4 pour une durée d’utilisation supérieure à 5 ans, comparativement à l’absence de traitement).
Le traitement transdermique n’était pas concerné par cette augmentation.
Référence :
Julie Berggreen
Contemporary menopausal hormone therapy and thrombotic disease: nationwide nested case-control study
BMJ 2026;394:e100688
Contemporary menopausal hormone therapy and thrombotic disease: nationwide nested case-control study
BMJ 2026; 394 doi: https://doi.org/10.1136/bmj-2026-100688 (Published 23 September 2026)Cite this as: BMJ 2026;394:e100688 Linked OpinionWe still do not know the answers to fundamental questions about menopause
Abstract
https://www.bmj.com/content/394/bmj-2026-100688
Objectives To investigate associations between current use of menopausal hormone therapy and development of venous thromboembolism, ischaemic stroke, and myocardial infarction.
Design Nationwide nested case-control study.
Setting National Danish health registries.
Participants 9807 women with venous thromboembolism, 18 460 women with ischaemic stroke, and 11 974 women with myocardial infarction were identified in a cohort of women of 50-69 years living in Denmark between 2003 and 2021 without a medical history of venous thrombosis, arterial thrombosis, cancer, liver disease, thrombophilia, oophorectomy, infertility treatment, endometriosis, or polyendocrine metabolic ovarian syndrome (PMOS, previously known as polycystic ovary syndrome). Cases were matched by birth year to a total of 49 035, 92 300, and 59 870 women without thrombotic disease, respectively.
Main outcome measures Receiving a first time diagnosis of venous thromboembolism, ischaemic stroke, or myocardial infarction.
Results Among women who had not used menopausal hormone therapy, incidence rates of venous thromboembolism, ischaemic stroke, and myocardial infarction per 10 000 person years were 15.8, 20.3, and 13.0, respectively. Compared with no current use, current use of oral oestrogen therapy (alone or combined with progestin) was associated with increased rates of venous thromboembolism (hazard ratio 1.6, 95% CI 1.5 to 1.8), ischaemic stroke (1.3, 1.2 to 1.4), and myocardial infarction (1.2, 1.1 to 1.3). The absolute risk increase per year was 0.09% (95% confidence interval (CI) 0.08 to 0.13%) for venous thromboembolism, 0.06% (0.04 to 0.08%) for ischaemic stroke, and 0.03% (0.01 to 0.04%) for myocardial infarction, corresponding to numbers needed to harm for one year of use of 1055 (95% CI 791 to 1266), 1642 (1232 to 2463), and 3846 (2564 to 7692), respectively.
Use of oral forms of oestradiol was consistently associated with increased venous thromboembolic risk compared with no current use. Oral oestradiol doses >1 mg/day used for more than one year was associated with increased risks of ischaemic stroke and myocardial infarction, with risks increasing with treatment duration (stroke hazard ratio 1.8, 95% CI 1.4 to 2.2 and myocardial infarction hazard ratio 1.8, 1.4 to 2.4 for >5 years of use compared with no current use).
Transdermal therapy was not associated with increased thrombotic rates compared with no current use, with the exception of increased risk of myocardial infarction with transdermal combined cyclic therapy (hazard ratio 2.1, 95% CI 1.1 to 4.1).
Conclusions Compared with no current use of any hormone therapy, oral menopausal hormone therapy was associated with increased venous thromboembolic risk regardless of dosage and treatment duration, while prolonged use of high dose oral oestradiol (>1 mg/day) showed elevated risks of ischaemic stroke and myocardial infarction. No increased thrombotic risks were observed with transdermal therapy.
What is already known on this topic
Oral menopausal oestrogen therapy has been associated with increased risk of venous thromboembolism and stroke, but evidence for an increased risk of myocardial infarction remains inconsistent
Evidence suggests that no increased thrombosis risk exists with use of transdermal menopausal hormone therapy
Studies comparing the risk of thrombosis across contemporary methods of use, regimens, active ingredients, dosages, treatment durations, and ages at treatment initiation remain limited
What this study adds
In this nationwide study, current use of oral menopausal hormone therapy was associated with an increased risk of venous thromboembolism across treatment characteristics, whereas increased risks of ischaemic stroke and myocardial infarction were observed only with oral high dose therapy used for more than one year
The numbers needed to harm for one year of oral therapy were 1055 (95% confidence interval (CI) 791 to 1266) for venous thromboembolism, 1642 (1232 to 2463) for ischaemic stroke, and 3846 (2564 to 7692) for myocardial infarction
Transdermal therapy was not associated with elevated thrombotic risk regardless of dosage and duration of use, supporting the importance of method of use in minimising risk of thrombosis
Conclusion
Current use of any oral menopausal hormone therapy was associated with an increased venous thromboembolism risk, whereas ischaemic stroke and myocardial infarction risk was only increased with oral high dose therapy used for more than one year. Transdermal therapy was not associated with increased thrombotic rates regardless of regimen, active ingredients, dosage, and duration of use.
