Incidence of venous thromboembolism in women receiving transdermal oestradiol/testosterone with micronised progesterone in accordance with NICE guidelines.

Background: Despite growing evidence supporting the long-term safety of hormone replacement therapy (HRT), concerns persist about certain adverse health outcomes, including venous thromboembolism (VTE). The aim of the study is to evaluate the risk of VTE in peri- and postmenopausal women treated with transdermal 17β-oestradiol with micronised progesterone or intrauterine progesterone (levonorgestrel) via the Mirena coil, in a real-world clinical setting. Methods: The study included peri- and postmenopausal women attending a private menopause clinic between January 1, 2023, and December 31, 2023. Patients were actively undergoing treatment with transdermal oestradiol and progesterone in the form of micronised oral progesterone or the Mirena intrauterine system, prescribed either by the clinic or their general practitioner. The incidence of VTE was recorded at each clinical appointment, with descriptions of any precipitating factors potentially contributing to any thromboembolic event. Data concerning oestradiol dose and preparation, testosterone use, and age were extracted from medical records and analysed using descriptive statistical methods. Results: A total of 13,026 women treated with transdermal oestradiol were included in the study. Of these, 11,071 women (85%) were also prescribed transdermal testosterone. The overall incidence of VTE in the cohort was 7/13,026 (0.054%). Conclusions: These findings indicate that transdermal oestrogen combined with micronised progesterone/Mirena does not appear to increase the risk of VTE compared to the expected population risk for women of similar age.