Now all that remains is for the fetus to be absorbed in the uterus
Denise Grady New York Times
Illustration: Gila Kaplan, Haaretz, Walla!
The future of the 30-year-old woman, who had breast cancer, does not look promising. Although chemotherapy might cure her, she knew it would almost certainly damage her ovaries and prevent her from conceiving.
The woman refused to lose hope and chose to participate in an experimental procedure, which may allow her to give birth in the future. Before she started the chemotherapy treatments, one of her ovaries was removed and frozen.
Six years have passed since then, in which no symptoms of cancer have appeared. Doctors from Weill College of Medicine at Cornell University in New York, led by Dr. Kotluk Oktai, thawed the ovary and implanted tissue taken from it under the skin of the patient's abdomen. With the help of hormone injections, the tissue began to release eggs.
In an article published yesterday in the online version of the medical journal "The Lancet", Dr. Oktai's team reports that this is the first case in which a healthy embryo was created from an egg that was released from ovarian tissue that had been frozen and thawed.
The embryo is created in the laboratory, by fertilizing the egg with the sperm of the woman's husband. After fertilization, the embryo was implanted in the woman's uterus. She was not able to conceive, but according to the doctors, the very formation of a healthy fetus is a promising progress, which brings hope for many cancer patients.
It is not clear why the patient was unable to conceive, but in vitro fertilization the chances of conceiving in one attempt, with only one egg, are not high, and several attempts are often required.
In a commentary accompanying the article, Dr. Johan Smits from the Free University in Brussels warns that it should be made clear to patients that ovarian freezing is still an experimental treatment and that children born as a result of this procedure will need strict medical supervision.
The team of doctors has already reimplanted thawed ovarian tissue in three other patients. The patients must be chosen carefully. According to Oktai, women younger than 37 are the best candidates for ovarian freezing because they have a large enough number of eggs to survive freezing and thawing. Also, "the experimental treatment of women who had breast cancer was done in consultation with their oncologists," says Dr. Zev Rosenwax, a member of Dr. Oktai's team. "We carefully check that the patients have recovered and that the oncologists believe that the procedure can be performed safely."
According to Dr. Oktai, he and his colleagues are trying to increase the number of eggs that can be used for fertilization. In the aforementioned case, the healthy embryo was created from an egg that had to mature in the laboratory before it could be fertilized. According to Oktai, the team is now focusing its efforts on immature eggs, because eggs that are ripe at the time they are collected from the ovary may be too "old."
Ultimately, Oktai adds, pregnancy should be possible. In the fall, researchers from Oregon Health Sciences University reported that a similar technique led to the birth of a healthy rhesus monkey. In this case the embryo was implanted in the womb of a surrogate mother.
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