What Is Retrograde Menstruation?

Retrograde menstruation is when blood flows backward into the pelvis instead of out of the vagina during menstruation. This is common and actually occurs to some degree in most women who have their period.

Some scientists believe that women with significant retrograde menstruation may be at increased risk for endometriosis—a condition in which cells that typically line the uterus appear on the outside of it. However, not all research supports this.

This article reviews the symptoms, causes, and diagnosis, and discusses why treatment is not necessary.

Retrograde Menstruation Symptoms

People with retrograde menstruation often do not have any symptoms. The primary symptom associated with retrograde menstruation is pain during menstruation (dysmenorrhea).

Unfortunately, this is not very telling, since menstrual pain is also associated with many other conditions affecting reproductive health.

Nevertheless, be sure to mention any extreme or unusual period pain or changes in your period to your healthcare provider.

Causes of Retrograde Menstruation

During retrograde menstruation, blood flows through the Fallopian tubes and out into the peritoneum (the lining of the abdominal wall), rather than through the cervix and out the vagina.

Most research about retrograde menstruation looks at it in the context of endometriosis. There is very little research on the causes of retrograde menstruation themselves.

There is also basic research suggesting that having a smaller cervical opening may increase the risk of retrograde blood flow.

Still, as research suggests that retrograde menstruation is extremely common among people who have a uterus, it should probably be considered a normal aspect of menstrual function.

Diagnosis

Retrograde menstruation is not usually diagnosed as a condition on its own. It may be diagnosed in the context of endometriosis or pelvic pain evaluation.

For example, retrograde menstruation might be diagnosed if healthcare providers do a laparoscopic examination of the pelvis during menstruation and they see blood.

Unfortunately, many women with endometriosis spend years in pain before they receive a diagnosis. Healthcare providers may attribute symptoms to the more common pain associated with periods or even consider painful periods to be normal.

Discomfort during menstruation is common. However menstrual pain should not be disabling or affect a woman’s ability to live her life.

Healthcare providers should consider a variety of causes, not just assume pain is due to primary dysmenorrhea. Endometriosis is thought to affect as many as 11% of women. It may not be easy to diagnose, but it’s important to check for it when there are signs.

Treatment

Retrograde menstruation is only a medical concern if and when it leads to symptoms or other conditions, such as endometriosis. As such, it is not treated unless it is causing other problems.

When it is treated, prescription hormones or a hormonal IUD may be recommended to reduce or eliminate menstrual flow.

A hysterectomy can also treat retrograde menstruation, but would only be used if there is another reason to remove the uterus.

Summary

Retrograde menstruation may sound scary, but remember that it isn’t all that uncommon. It just means that when you get your period, some of the blood and tissue are flowing backward into your pelvis rather than out onto your pad, or into your cup or tampon.

In general, retrograde menstruation is not something you need to worry about. If it is associated with other problems, such as endometriosis, those will be treated directly by your healthcare provider.