Retrograde menstruation (RM) occurs when a portion of the menstrual flow, containing blood and endometrial tissue, travels backward through the fallopian tubes and into the pelvic cavity instead of exiting the body. This process is extremely common, occurring in up to 90% of individuals who menstruate. The challenge arises when the body’s immune system fails to clear this misplaced tissue, allowing the cells to implant and grow outside the uterus, a condition known as endometriosis. Since RM is a frequent physiological event and not a disease, medical intervention focuses on managing endometriosis and its associated symptoms.
Why Retrograde Menstruation Cannot Be Directly Stopped
Stopping the backward flow of menstrual tissue is not a direct goal of treatment because the phenomenon is a widespread, natural occurrence. The fallopian tubes provide a direct pathway for this retrograde flow. Blocking this anatomical route is not medically feasible or advisable, as it does not address the underlying issue.
Endometriosis is caused by the body’s inability to clear the tissue that flows back, not by RM alone. In most individuals, the immune system effectively recognizes and removes the displaced endometrial cells from the pelvic cavity. Therefore, treatment strategies must target the growth and activity of the implanted tissue rather than trying to physically halt the menstrual flow.
Hormonal Treatments to Manage Endometriosis
Hormonal treatments are the first-line therapy for managing the pain and progression of endometriosis. These medications function by suppressing the menstrual cycle and reducing the body’s overall exposure to estrogen. Estrogen stimulates the growth of both the uterine lining and the ectopic endometrial implants. By creating a state of reduced hormonal activity, these therapies decrease the amount of tissue available to flow backward and lessen the stimulation of existing lesions.
Combined oral contraceptives (COCs), often taken continuously, suppress ovulation and stabilize hormone levels, leading to a thinner uterine lining. This reduction limits the production of inflammatory mediators, such as prostaglandins, which cause severe cramping and pain. Progestin-only medications, including injections, implants, or intrauterine devices (IUDs), induce atrophy of the endometriotic tissue. Progestins also suppress the release of gonadotropins, contributing to a low-estrogen environment that hinders lesion growth.
GnRH Agonists and Antagonists
Gonadotropin-releasing hormone (GnRH) agonists and antagonists are a more potent class of hormonal therapy. These treatments induce a temporary, reversible menopausal state by suppressing the pituitary gland’s release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The resulting hypoestrogenic state starves the endometrial implants of the hormone needed for growth. While highly effective, these treatments are often used for limited durations to mitigate side effects related to low estrogen.
Surgical Procedures and Advanced Interventions
When hormonal management is insufficient or when fertility is a primary concern, surgical intervention is the next step. The goal of surgery is to remove the established lesions, cysts, and scar tissue that have formed outside the uterus. This procedure is typically performed laparoscopically through small incisions, allowing for the precise visualization and treatment of the implants.
Excision and Ablation
Laparoscopic excision, where the surgeon cuts out the entire lesion, is often the most effective surgical technique for long-term symptom relief. Alternatively, ablation uses heat or other energy sources to destroy the surface of the deposits. Excision is preferred for deeper lesions, as it ensures the complete removal of the tissue, minimizing recurrence.
Hysterectomy
For severe and recurrent cases, especially for those who have completed childbearing, a hysterectomy—the removal of the uterus—may be considered as a last resort. This procedure eliminates the source of the menstrual flow. To reduce the risk of symptom return, the ovaries are sometimes removed along with the uterus, as they are the primary source of estrogen that fuels any remaining endometriotic implants.