- Menopause describes the point in life when the last menstrual cycle occurs, which happens around the age of 50 in women. Ovarian reserve depletes in the years, and decades, before menopause occurs.
- Many welcome the end to periods and worries about unwanted pregnancy, but menopause, and the perimenopause before it, is often accompanied by troubling symptoms such as hot flashes, cognitive problems, night sweats, vaginal dryness, anxiety, and a reduced sex drive.
- Now, researchers may have found a way to delay, and perhaps even prevent, menopause.
- A modeling study suggests that by removing, freezing, and then reimplanting ovarian tissue, the fertile years can be extended long beyond the normal age of menopause.
Menopause, which for most women happens between the ages of 40 and 58, signals the end of the reproductive years. Although the end of monthly periods and worries about birth control is often welcome, many people will experience a less welcome range of physical and mental symptoms.
These symptoms, which may include hot flashes, night sweats, vaginal dryness, anxiety, and a reduced sex drive, can start long before menopause and continue for several years afterward. So, could a treatment that delays, or even prevents, menopause be beneficial?
Researchers at Yale School of Medicine believe that it would and may have found a way to do it. They suggest that by freezing ovarian tissue taken from a woman during her reproductive years and then reimplanting it at a later stage, they could delay, or even prevent menopause.
The mathematical modeling study is published in theAmerican Journal of Obstetrics and Gynecology.
“This is very interesting data on the forefront of science-cryopreservation of the ovaries — especially useful for people undergoing chemotherapy and/radiation for cancer treatment. These techniques can protect and preserve the ovarian tissue for reimplantation. The modeling, predicting how long menopause can be delayed is interesting but not currently useful in practice.”
— Dr Robin Noble, chief medical officer at Let’s Talk Menopause, speaking to Medical News Today.
Ovarian tissue transplants
Ovarian cortex is the outer part of the ovary, where most of the follicles — the structures that mature each month to release an egg at ovulation — are found. For freezing and transplant, the cortex can be from a donor or from the person undergoing the treatment.
Now, scientists led by Prof. Kutluk Oktay, M.D., Ph.D., have suggested that the technique could be used to preserve fertility and prevent troubling symptoms by delaying or even preventing menopause.
The researchers used data from previous studies of ovarian reserve at different ages, and on how ovarian follicles behave in ovarian tissue. From this, they created a mathematical model that predicts how long ovarian transplant surgery might delay menopause in healthy women.
They incorporated several factors, including age and follicle survival, in their model to see how long different factors might delay the time of menopause.
How effective is ovarian transplanting?
The model predicted that for most women ages 40 and under, ovarian tissue cryopreservation and transplant would significantly delay menopause.
The success of the transplant depended on four factors:
- Age at ovarian tissue harvest (21-40 years)
- Amount of ovarian tissue harvested
- Single vs. Multiple transplants of harvested tissues
- The proportion of follicles that survived post-transplant.
Tissue harvested after the age of 40 years did not delay menopause onset as there were too few viable follicles left in the tissue of the typical donor.
“The younger the person, the larger number of eggs she has, as well as the higher the quality of those eggs,” Prof. Oktay said. The amount of tissue harvested was key — too little and menopause would not be delayed, but if too much was taken, this might bring on an early menopause. However, the model accounted for this: “This model gives us the optimum amount of tissue to harvest for a person of a given age,” he added.
To illustrate their model, the researchers give the example of a 25-year-old who had 25% of her ovarian cortex tissue harvested, and then transplanted in one procedure. If 40% of the follicles survived, this might delay menopause by almost 12 years; if 80% survived, the delay would be around 15.5 years. Authors noted that currently, ovarian transplant procedures are associated with a 60% loss of follices and that 80% survival could only be achieved if technology and techniques progressed in coming years.
However, if they divided up the tissue and transplanted it in several procedures, menopause delay was increased. At 40% follicle survival, three transplants extended the delay to 23 years, and six transplants to 31 years. If 80% of follicles survived, the model predicted that menopause might be delayed by as much as 47 years, which, for most women, would mean that they would never experience menopause.
Should menopause be delayed?
“If we can adequately replace the hormones (that should continue to improve with more research into this area), would we want to delay the time of natural menopause? Many women struggle with issues during their reproductive years — PCOS, endometriosis, fibroids, painful periods, heavy periods, undesired fertility, premenstrual dysphoric disorder — would they want to prolong their cycles? I think not. Would they want to delay or avoid the symptoms of menopause — very likely. And we can do that with menopausal hormone therapy (MHT) without exacerbating those other symptoms.”
— Dr. Robin Noble
Menopause is considered a
However, for others, perimenopause and menopause may mean several years of troubling symptoms that can affect their quality of life. As we live longer, many women will spend around one-third of their lives postmenopausal, so they may wish to shorten that time.
Apart from delaying symptoms,
“Do we need cryopreserved ovaries to accomplish these goals?” Dr. Noble questioned.
“With MHT, we can give back some of these hormones at various doses, with the option of tailoring to the symptoms and goals of the person, understanding the risks and benefits of various treatment options. Moreover, MHT avoids the cyclic symptoms (often bothersome bleeding, mood changes, bloating, breast tenderness, cyclic migraines) that would be present in the case of preserved ovaries,” she explained.
But the option of surgery to remove and then replace cryopreserved ovarian tissue should not be taken lightly, as it does involve repeated abdominal or keyhole (laparoscopic) surgery. So, a woman would need to think carefully about whether, for her, the benefits of delaying menopause outweigh the risks.
Dr. Noble is not convinced that the technique offers many benefits:
“Menopause is a natural stage of life. It is not a disease. It is not an illness anymore than aging is an illness. After menopause, we see significantly increased risks for cardiovascular disease, bone loss (osteoporosis), diabetes, obesity, colon cancer risks, which seem to be mitigated with MHT.”
“People need better information about the options for management of this stage of life so they can be empowered by the latest research to make the best decisions for themselves, as there are many treatment options available for the symptoms of menopause,” she added.
