Transdermal estrogen therapy in menopausal women at increased risk for thrombotic events: a scoping review

It is estimated that over 45% of women in the United States are menopausal. Many of these women suffer from vasomotor symptoms of menopause, for which the gold standard treatment is menopause hormone therapy (MHT). However, MHT use has been controversial since the Women's Health Initiative (WHI) study in 2001. Transdermal MHT has been shown to be effective for treatment of vasomotor symptoms and does not increase the risk of venous thromboembolism (VTE) when used in healthy postmenopausal women. However, there is little data on its safety in women at increased risk for VTE such as women with prior VTE, increased body mass index, thrombophilia, tobacco use, autoimmune disease, chronic inflammatory disorders, recent surgery, trauma, or immobilization. This scoping review of the literature provides clinicians with an overview of the evidence on the risk profile of transdermal MHT use in these postmenopausal women at increased risk of VTE.We searched all published studies from 2000 to 2020 and included 13 primary articles on transdermal MHT use in postmenopausal women at increased risk of VTE.In women with prior VTE, two studies found a decrease in coagulability and no increased risk of recurrent VTE with transdermal MHT use. In women with increased body mass index, three studies found no increased VTE risk in transdermal MHT users. In women with prothrombotic genetic polymorphisms, three studies found minimal to no increased VTE risk in transdermal MHT users. In women with various proinflammatory comorbidities, five studies found an improved thrombotic profile and no increased VTE risk with transdermal MHT use. This scoping review provides data regarding the safety of transdermal MHT use in postmenopausal women with risk factors for VTE, and clinicians should have risk versus benefit discussions with each patient regarding its use.