Detailed definition
Venous thromboembolism encompasses deep vein thrombosis (typically in the legs) and pulmonary embolism (clot lodging in the pulmonary arteries). Baseline VTE incidence in healthy postmenopausal women is roughly 1–2 per 1,000 per year, increasing with age, obesity, immobility, smoking, and inherited thrombophilias (factor V Leiden, prothrombin 20210A, antithrombin/protein C/S deficiency). Oral estrogen — both CEE and oral estradiol — roughly doubles VTE risk through first-pass hepatic stimulation of clotting factor synthesis. Transdermal estrogen does not significantly elevate VTE risk in observational studies (ESTHER, MEGA) because it bypasses hepatic first-pass metabolism. For most healthy women in the timing window, the absolute increase in VTE risk on oral estrogen is small (an extra 1–2 events per 1,000 per year on top of a low baseline). For women with VTE risk factors, transdermal is strongly preferred.
Why it matters in menopause
For women with personal or family history of VTE, obesity, prolonged immobility, or known thrombophilia, transdermal estradiol is the appropriate choice — not oral. ClearedRx screens for VTE history at intake and uses the answer to choose route accordingly.
Related terms
Sources
External references: Wikipedia.