Ovarian Transplantation is Effective, Even After Cryopreservation

by Michelle Rizzo

Reuters Health
March 8, 2010

NEW YORK (Reuters Health) - Ovarian transplantation, first done successfully in 2005, is now a "robust procedure," even after cryopreservation, researchers say.

They found good long-term function of fresh and frozen ovarian grafts in women followed for up to 5 years.

"This is the largest series of ovarian transplants to date with the largest number of pregnancies and live births, and the longest number of follow up years to evaluate the efficacy of ovary transplantation, fresh or frozen, and the expected duration of function," lead investigator Dr. Sherman Silber, from St. Luke's Hospital in St. Louis, Missouri, told Reuters Health by email. "It provides otherwise rare information for guiding fertility preservation practices and counseling patients about the likelihood of success."

In a paper published online February 19th in Fertility and Sterility, Dr. Silber and his colleagues report on two groups: 9 women with premature ovarian failure who received ovaries from monozygotic twins, and 16 with cancer who had their ovaries cryopreserved.

All of the women who received fresh ovarian tissue had return of their regular menses and ovulatory cycles, and normal serum FSH levels returned within 5 months after surgery.

Two women (one with premature ovarian failure and one with a history of Hodgkin's lymphoma) had three transplants of frozen cortical tissues. Each frozen tissue transplant produced a spontaneously conceived pregnancy, with one delivered and two still ongoing.

In the 16 cancer patients, the authors compared tissues preserved by vitrification versus slow freezing. Oocyte survival with slow freezing was 42%, compared to 89% after vitrification.

Altogether, 14 spontaneous pregnancies have resulted in eight healthy babies, two healthy ongoing pregnancies, and four miscarriages.

"These patients after fresh or frozen ovary transplantation had essentially a completely normal pregnancy rate and delivery rate as you would expect in any normal group of women who had never had the cancer or undergone ovary transplantation to cure their premature menopause," Dr. Silber told Reuters Health.

"One in every 250 young women today are cancer survivors, but their cancer treatment has rendered them sterile," he continued. "With this approach of ovarian tissue freezing [video] and transplantation, we can now preserve their fertility, and rather inexpensively."

Dr. Silber proposes that "one has to consider whether this could be offered also to young women who need to put off childbearing aspirations until they are in their late 30s or 40s, as so many women in our modern society must do."

The ultimate implication of these findings, he said, is to "prolong the reproductive lifespan not only of cancer patients but of any young woman who needs to postpone childbearing."

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