Can menopause be delayed in healthy women, allowing them to extend their child-bearing years—and perhaps even forestall some of the health risks and uncomfortable symptoms linked to plummeting estrogen levels?
Delaying menopause with ovarian cryopreservation (freezing) also may confer certain health benefits associated with a later menopausal age. Based on new research at Yale around 11% of women experience late-onset natural menopause—or menopause after age 55. Studies show that women who experience menopause later may live longer and have a lower risk for a range of conditions, including cardiovascular disease, dementia, retinal disease, depression, and bone. The Yale group headed by Kutluk Oktay MD, PhD hypothesizes that those risks also may be mitigated in healthy women who delay menopause via ovarian tissue cryopreservation.
In an earlier publication, the Yale group predicted that, for most women aged <40 years, ovarian tissue cryopreservation and later transplantation would result in a significant delay in menopause. The advantage is greater if the follicle loss after transplant can be minimized. Ovarian follicles are small fluid-filled sacs that contain one egg. There are thousands of follicles in the ovary. As an example, the delay in menopause (D) for a woman with a median ovarian reserve who cryopreserves 25% of her ovarian cortex (outer layer of the ovary) at the age of 25 years and for whom 40% of follicles survive after transplantation would be approximately 11.8 years, but this extends to 15.5 years if the survival is 80%. As another novel finding, spreading the same amount of tissue to repetitive transplants significantly extends the benefit. For example, for the same 25-year-old woman with a median ovarian reserve, 25% cortex removal, and 40% follicle survival, fractionating the transplants to 3 or 6 procedures would result in the corresponding delay in menopause (D) of 23 or 31 years. The same conditions (3 or 6 procedures) would delay menopause as much as 47 years if posttransplant follicle survival is improved to 80% with modern approaches. An interactive Web tool was created to test all variables and the feasibility of ovarian tissue freezing and transplantation to delay ovarian aging.
The researchers concluded that with harvesting at earlier adult ages and better transplant techniques, a significant menopause postponement and, potentially, fertile life span extension can be achieved by ovarian tissue cryopreservation and transplantation in healthy women.
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