A medical procedure that has been used to freeze a woman's ovaries is being offered for the first time as a way to delay menopause for up to 20 years, according to news reports. But not everyone's convinced.

This procedure, called "ovarian tissue cryopreservation," isn't something new. It was developed back in the late 90s and is commonly performed to preserve the ovaries of girls and young women undergoing tissue-damaging cancer treatment. Doctors take out parts of the ovaries and freeze them before such patients undergo chemotherapy and radiation treatment. In the future, if these patients want to have children, doctors reimplant the ovarian tissue in the body.

But now, the U.K.-based company, ProFam, is offering the same procedure for women up to the age of 40 who just want to delay menopause — the time when levels of reproductive hormones fall, and a woman stops getting her menstrual period. For many women, this life period is marked by uncomfortable symptoms, including hot flashes and mood swings; and sometimes even more serious health problems such as heart conditions and osteoporosis.

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The company has already performed this procedure, which costs around 7,000 to 11,000 pound sterlings($8,500 and $13,300), on nine women. The idea is that once the women enter menopause, the tissue can be reimplanted into their bodies and restore their sex hormones — thereby pausing menopause, according to The Guardian .

However, its effectiveness will depend on the age of the woman when her tissue is taken. Tissue frozen from a younger patient and implanted later in her life might delay menopause for decades, whereas tissue frozen from an older patient might delay it only for a few years, according to The Guardian.

"We know that when tissues are frozen, transplanting can work," said Dr. Kutluk Oktay, a reproductive biologist at the Yale School of Medicine and an infertility specialist and medical director of the Innovation Fertility Preservation Institute in New York. The idea that it can delay menopause by up to 20 years, as news reports say, is "very speculative," said Oktay, who is not involved with ProFam but was the first to perform the first successful ovarian transplantation with cryopreserved tissue in 1999.

In addition, the literature doesn't clarify how much ovarian tissue doctors should remove for this purpose, and how the procedure will affect the time span of the delay, he told Live Science.

"By removing tissue, you would actually shorten that person's reproductive window," he said. By the time the tissue is implanted, it's not the same as fresh tissue and will have lost half or more of its follicles (the structures that eventually give rise to mature eggs), he said. So, "what you're putting in is not the same as what you're taking out," Oktay said.

With cancer patients, there's a somewhat clearer benefit to performing this procedure, because they will lose that ovarian tissue anyway, he said. For healthy patients, it's possible that with more research, it can be developed into a procedure that will clearly and effectively delay menopause, but for now, "we still don't know the equation" for the risk versus the benefit, he said.

ProFam did not immediately respond to a request for comment.

Editor's Note: This article was updated to clarify Dr. Kutluk Oktay's job title and that he performed the first successful ovarian transplantation with cryopreserved tissue in 1999, not the cryopreservation itself.