For decades, doctors have been working to preserve a woman's fertility while they undergo cancer treatments, which destroy the ovaries.
Some women undergo "egg ripening and harvesting" treatments, which use hormones to include her body to make multiple eggs ripen at once, which are then harvested and frozen for later use. These methods aren't suitable for girls who are too young to be fertile, and for women who have hormone sensitive cancers or those who need to be treated immediately.
So, women are more and more often opting to preserve their fertility with an ovarian tissue transplant: By removing and freezing ovarian tissue for re-implantation later. When they are in remission and want to try to have children, doctors can implant the tissue into their abdomen and, theoretically, it will start producing eggs from the immature egg cells.
This procedure has actually been successful with multiple cancer patients, resulting in 22 births so far. Here's how it works.
Quick and easy removal.

The doctors remove a part of a healthy ovarian cortex using laparoscopic surgery, which takes about 30 to 45 minutes, from the young woman about to undergo cancer treatment.
Slice and dice.

The ovary's outer layer of tissue (called the cortex) is cut into tiny 1 millimeter thick strips that are frozen for later while the woman undergoes cancer treatment. The cancer treatments like chemotherapy and radiation have a high likelihood to cause infertility because they specifically attack fast growing cells, like those that give rise to a fertile woman's eggs.
Baby time is coming.

After the patient goes into remission and wants to become fertile again the doctors can plan a surgery.
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