So we have been talking about a pretty common post-menopausal diagnosis this month – Genitourinary syndrome of menopause.

We’ve gone through signs and symptoms, and how to do a good self exam. But why do these changes happen? To tell a long story short: a loss of estrogen. To tell a short story long, we have to start back during the reproductive years.

To start, the female body makes 3 forms of estrogen: estradiol, estrone, and estriol. During the “reproductive” years of your life (between puberty and puberty 2.0 aka menopause), your body makes the most estradiol. This is the most effective form of estrogen, and in response, your urogenital tissues (urethra, vagina) have a plethora of estrogen receptors. Estrogen makes those tissues look pink and plump. This increase in blood flow to the area also helps to keep tissue lubricated. Activated estrogen receptors also allow for growth of the vaginal lining, which causes redundancies called rugae. This makes the vagina more elastic and expandable. This increase in blood flow, growth of tissue, and lubrication all allow for the vagina to be more tolerant of penetration with less resulting physical trauma (pain, tearing, etc). Estrogen also helps cells make byproducts that cause the vagina to be super acidic. This low pH, high acidic state is what allows for the vagina to keep bad bacteria from growing – we’re looking at you e.coli, BV, AV, etc, reducing the risk of infections like UTIs.

A year after your last period, your body stops making estradiol and makes more estrone, which is a less effective form of estrogen. The number of estrogen receptors in your urogenital tissues decreases as well, since there is less estrogen to go around. In response, the tissues of your vulva become less elastic by forming connective tissue that is more dense, less lubricated (due to a lack of blood flow), and more thin (due to a lack of cellular growth). The same process that causes the lining of your vagina to thin also contributes to the lack of byproducts that help keep your vagina acidic, thus making it easier for bad bacteria like e.coli to grow. This also results in a shortened, more narrow vagina, which can contribute to painful penetration.

The above picture shows the changes in the rugae. On the left is a pre-menopausal vagina, on the right, a post menopausal vagina. This lack of rugae significantly decreases vaginal elasticity, expandability, and thus, tolerance for penetration.

Estrogen may also play a role in your brain’s ability to tell when your bladder is completely full, resulting in higher likelihood of incontinence. 

The great news is, vaginal estrogen (in either pill or cream form) can reverse a lot of these effects. With regular exposure to estradiol, the cells in the vaginal build back up their estrogen receptors and help the urogenital tissues get close to their pre-menopausal state.

Sometimes, there are also muscular changes that occur to the pelvic floor that can help these symptoms persist. Check back next week to learn about pelvic floor PT’s role in the treatment of GSM!

-Naomi

1. Genitourinary syndrome of menopause: an overview of clinical manifestations, pathophysiology, etiology, evaluation, and managementGandhi, Jason et al.American Journal of Obstetrics & Gynecology, Volume 215, Issue 6, 704 – 711