Unscheduled bleeding on HRT - do we always need to investigate for endometrial pathology?

Abstract

Hormone replacement therapy (HRT) is the most effective method for relieving the effects of hypoestrogenism following menopause. Despite the benefit of the HRT, unscheduled/breakthrough bleeding decreases patients’ compliance with long-term use. The underlying mechanisms for this unpredictable breakthrough bleeding are less well understood. In the event of unscheduled bleeding, investigation may be necessary according to local protocol. Whilst the incidence of underlying benign pathology may be quite high, the likelihood of malignancy is low and unless there is particular clinical concern, these women do not need fast track referral which should be reserved for women with true postmenopausal bleeding.

Unscheduled bleeding with hormone replacement therapy

“…In women without a uterus, estrogen‐only therapy is used. Continuous combined HRT can be prescribed if there is a history of severe endometriosis or occasionally after subtotal hysterectomy after careful consideration by the clinician …”

“…With regard to the transdermal route, irregular bleeding or spotting occurs in 10–20% of women after 12 months of use . In the sequential regimen, irregular bleeding is experienced by 8–40% of users . More than half of users of this regimen may bleed before day 11 of the progestogen sequence, and less than 10% of women may experience recurrent episodes of breakthrough bleeding .…”

“…In the sequential regimen, irregular bleeding is experienced by 8–40% of users . More than half of users of this regimen may bleed before day 11 of the progestogen sequence, and less than 10% of women may experience recurrent episodes of breakthrough bleeding . Due to unscheduled bleeding on HRT, 25–50% of women discontinue HRT .…”

“…Overall, the incidence of benign pathology may be significant, yet the likelihood of malignancy is low in the majority of women on HRT …”

“…Among women with postmenopausal bleeding, a thin endometrium (<5 mm) safely excludes endometrial pathology and may not require any further investigation unless recurrent/persistent bleeding or any high‐risk factors are present …”