Perimenopause is a harsh reality when you’ve lost an ovary to endometriosis. And, one and a half years after my ovary removal surgery, I’m beginning to experience this phenomenon first hand. However, perimenopause isn’t the only complication associated with removing an ovary; disorders such as diminished ovarian reserve and primary ovarian insufficiency share similarities with perimenopause. In turn, this makes it a  challenge to diagnose and treat the root cause of symptoms properly.  Learning more about these disorders and how removing an ovary increases the risk of these complications can help achieve a proper diagnosis and treatment.

What Is Perimenopause?

Menopause is a series of stages identified as perimenopause, menopause, and postmenopause. The onset of perimenopause kickstarts the gradual progression to menopause. The decreased production of estrogen and progesterone triggers symptoms such as irregular periods and mood changes. 

On average, perimenopause begins in the late ’30s and ’40s. And the transition to menopause lasts four to five years. And once menstruation doesn’t occur for 12 consecutive months, you’re considered to be menopausal and well on your way to becoming post-menopausal. 

Symptoms of Perimenopause

The most common perimenopause symptoms are:

  • Hot flashes
  • Breast tenderness
  • Intensified PMS symptoms
  • Low libido
  • Fatigue
  • Irregular periods
  • Vaginal dryness
  • Painful intercourse
  • Urinary incontinence
  • Frequent urination
  • Changes in mood
  • Difficulty sleeping
  • Insomnia

To be considered perimenopausal, you must display four or more of the above symptoms.

<img src="two women.png" alt="two women drinking coffee talking about perimenopause"/>

Can Removal of One Ovary Induce Perimenopause?

Unfortunately, there’s a lack of clear data explicitly addressing this phenomenon for those of us with one ovary. There are ample studies that indicate that removing both ovaries via bilateral oophorectomy will induce surgical menopause, caused by a steep decline in estrogen. But, this doesn’t elaborate on what this means for patients having undergone a unilateral oophorectomy. 

One article indicates that your ovary will retain normal function with negligible impact on fertility and no severe risk of early-onset menopause. However, another study suggests ovarian surgery is associated with an elevated risk of premature menopause. Indeed, my surgeon discussed that removing my left ovary may trigger early menopause and be observant of such symptoms.

In addition to the conflicting information from the medical community, the process of perimenopause itself is broad. Perimenopause symptoms can begin in the 30s and 40s. Having your ovary removed during this time and experiencing traditional perimenopause symptoms makes it difficult to determine if it’s associated with the natural aging timeline or accelerated because of a subtle downturn in estrogen. 

Furthermore, ovarian surgery is known to trigger other conditions. For example, diminished ovarian reserve and primary ovarian insufficiency mimic perimenopause symptoms while contributing to early-onset menopause, complicating the diagnostic process and making it difficult to get appropriate treatment. 

 

Diminished Ovarian Reserve And One Ovary

Risk factors that contribute to the onset of diminished ovarian reserve are managing a condition like endometriosis, undergoing ovary removal surgery, or receiving chemotherapy and radiation. 

But what exactly is the ovarian reserve? The ovarian reserve indicates the number and quality of eggs housed within the ovary. However, as we age, egg number and quality decrease.

On average, we’re born with 1-2 million eggs, and by puberty, we have 300,000 to 500,00. As we age and approach 37, the egg count is around 25,00, and by age 51, we have about 1,000. Of course, these numbers are estimates since individual factors influence egg count. Regarding ovarian surgery, having an ovary removed or experiencing ovary damage will decrease egg quality and amount. 

 

Symptoms Diminished Ovarian Reserve Shares with Perimenopause

To further muddy the waters, diminished ovarian reserve (DOR) and perimenopause share similar symptoms making it easy to mistake one for another. Symptoms these conditions share include irregular periods, shortened menstrual cycle, heavy menstrual flow, and infertility. 

However, DOR can be diagnosed with a blood test. The goal is to check the follicle-stimulating hormone (FSH) and anti-Mullerian hormone (AMH) levels. If you’ve undergone IVF or fertility treatments, you’re probably familiar with these two hormones and this specific test. It’s commonly used in fertility clinics to identify one’s eligibility and success rate for undergoing IVF.

If levels of FSH are high and range above 15, this can indicate a reduction of eggs within the ovarian reserve. On the other hand, AMH levels are dependent upon age. So, suppose you’re thirty with levels at 2.5; you probably have DOR. 

<img src="woman.png" alt="woman on phone in cafe reading about perimenopause"/>

 

Primary Ovarian Insufficiency And Its’ Link To Removal of One Ovary

As established earlier ovarian surgery can compromise the function of the ovary and contribute to perimenopause or cause primary ovarian insufficiency (POI). In either case, symptoms mimic each other to the extent that it’s nearly impossible to tell them apart. These symptoms include irregular periods, infertility, hot flashes, night sweats, vaginal dryness, dry eyes, decreased libido, and irritability. 

Additionally, POI causes ovarian follicular dysfunction caused by dwindling functional primordial follicles. A small amount of ovarian function and hormone levels do not decline as rapidly in some cases. Yet, a steep drop in hormone levels causes severe menopausal symptoms and decreased ovarian function for some. Both instances involve sporadic ovulation, instability within the menstrual cycle, and period irregularity.

Unlike perimenopause, some tests can diagnose POI. Typically these tests are administered when menstruation doesn’t occur within 4-6 months. Then, doctors administer two separate blood tests to observe the FSH levels within one month of each other. To be diagnosed with POI, FSH levels must be greater than 30 U/L, considered within the menopausal range. 

What Does Perimenopause With One Ovary Look Like?

The answer to this question isn’t concise; as a matter of fact, it is complex and nuanced. We understand that undergoing ovarian surgery and removing an ovary will cause different outcomes for every individual. If you’re preparing for surgery, discuss the possibility of perimenopause, early onset menopause, DOS, and POI. If you want to become pregnant post-surgery, work with a fertility specialist to determine your fertility outlook and rule out any complications with DOS.

On the other hand, if it’s post-surgery, speak with your gynecologist about DOS, POI, perimenopause, and early onset menopause. Remain on the lookout for any signs and symptoms. If you begin to notice them, request testing, as mentioned above.

Since it’s not common for doctors to test for perimenopause, having regular hormone testing doesn’t hurt. Testing FSH, AMH, and having a full hormone panel that tests thyroid hormones can provide more insight for you and your doctor.

Electing to become proactive about your health and well-being with ovary removal surgery is crucial. Regardless of where you are on this journey, it’s important to advocate and speak up for yourself.

 

Resources

Healthy Women Menopause And Chronic Health Risks by Jamie Seaton Aug 2020

 Healthline What Is Diminished Ovarian Reserve And What Can You Do About It? by Sian Ferguson February 2019

Healthline AMH Testing And What It Can Tell You by Sarah Lindberg October 2020 

International Journal of Women’s Health Primary Ovarian Insufficiency Leticia Cox, James H Liu

WebMD What Is Premature Ovarian Failure Traci C Johnson MD January 2020

Mayo Clinic Perimenopause

Clevland Clinic Perimenopause and Menopause

Our Bodies Ourselves Oophorectomy

Oxford Academic Human Reproduction Vol 29, Issue 4, April 2014, Pages 835-841 Is Unilateral Oophorectomy Associated with Age At Menopause? by E.K. Bjelland, P. Wilkosz, T.G. Tanbo, A. Eskild