Disturbances of endometrial bleeding with hormone replacement therapy

Breakthrough bleeding is a common problem in postmenopausal women taking ho rmone replacement therapy (HRT) and is often the single most important fact or deterring women from continuing to use HRT, or from starting it in the f irst place. The mechanisms which underlie this unscheduled bleeding are poo rly understood. The benefits of HRT in terms of longevity and quality of li fe are becoming increasingly apparent, and a greater understanding of why t his bleeding occurs and how we can prevent or treat it, will undoubtedly en able more women to reap the potential considerable benefits of long-term oe strogen and progestogen replacement. What sets postmenopausal women apart f rom their counterparts in the mid-reproductive years is the increased likel ihood of endometrial adenocarcinoma in which unscheduled bleeding is the pr esenting symptom. Therefore, spontaneous postmenopausal bleeding must alway s be appropriately evaluated. Hence, the occurrence of unscheduled bleeding with HRT may provide a dilemma with diagnosis as well as a challenge to ac ceptability. Combined HRT regimens tend to be predominantly progestogenic, and there is increasing evidence to suggest that some of the vascular chang es seen in women taking longterm, low-dose progestogen-only contraceptives may also occur in women taking HRT.