But in some cases, the twin pairs had very different ages of menopause, sometimes varying by as much as 20 years.
“The biggest mystery surrounds the identical twins because one would expect them to have similar menopause,” Gosden said. “That is true most of the time, but, in some cases, it’s extraordinarily early and may be different from the other twin.”
The reasons are unclear. However, Gosden said that scientists “know why identical twins [can be] very different in terms of their ovaries.”
“We do believe that the problem starts when the woman was actually a fetus, when the eggs were formed,” he continued. “We believe that the infertile sister doesn’t form a normal number of eggs, so she runs out of eggs earlier.”
“The ovary works like an hour glass with a fixed number of eggs,” Gosden explained. “When they’ve run out, the woman has menopause. We believe that the infertile twin has fewer eggs to begin with.”
Now Gosden is moving his research into the clinical stage.
“We’ve been receiving calls from twins where one has had an early menopause, and they’re interested in having a transplant from a fertile twin to an infertile twin to restore ovarian function,” Gosden said. So far, 10 patients have signed up, five of whom have already had transplants. All the transplants have been successful, and three women have become pregnant or delivered babies.
“One of the important things to take out of this study is that one twin could serve as an egg donor or donor of ovarian tissue in order to reverse early menopause for the other twin,” said Dr. Jennifer Wu, an obstetrician/gynecologist at Lenox Hill Hospital in New York
City. “We have so many advances these days in regard to fertility, so premature menopause is not the terrible thing it once was.”