For the first time, transplanted ovarian tissue from a fertile, 24-year-old woman to her prematurely menopausal identical twin has resulted in a normal pregnancy, according to a new study .

According to Dr. Sherman J. Silber, from St. Luke’s Hospital in St. Louis, and colleagues, the ovaries of the patient who had stopped menstruating were not functional. She had also failed two cycles of in vitro fertilization for which the healthy twin had donated eggs.

At the time of transplantation, the woman’s hormone levels were menopausal. Both patients underwent genetic testing, which revealed no obvious cause for concern about the health of future offspring.

During the transplantation procedure, tissue taken from the ovary of the healthy twin was sutured to both ovaries of the infertile twin.

Approximately three months later, during a second menstrual cycle, the transplant recipient’s levels of the hormones gonadotropin and estrogen had returned to levels found in young, fertile women. She conceived naturally without medical assistance during this cycle and gave birth to a healthy-appearing full-term girl.

“The demonstration that ovarian function can be restored and that natural conception and successful pregnancy can be achieved after transplantation of ovarian tissue may have broader implications for preserving fertility in young women, such as those who require potentially sterilizing treatment for cancer,” Silber and his associates conclude.

SOURCE: The New England Journal of Medicine, July 7, 2005.