Chemotherapy is harsh, which is good when it comes to killing cancer. What's not-so-good is that it can also cause hair loss, inflict nausea, and disable the proper functioning of all sorts of organs -- including the ovaries. Chemotherapy, therefore, can affect female fertility.

In some cases, doctors have extracted immature eggs from adult women about to receive chemotherapy, matured them in a laboratory, and then implanted them when the women are ready to have children. Until now, no one had ever tried this with eggs from young girls -- girls who have not yet undergone puberty. But it's just recently happened.

Doctors have removed eggs from young female cancer patients and for the first time, have brought the eggs to maturity before freezing them.

"We didn't expect young girls to have eggs that could withstand the process of maturation," which involves adding hormones, says lead researcher Dr. Ariel Revel.

In his study, Revel surgically extracted the eggs from 18 patients, ages five to 20. He then artificially matured them in a laboratory, with the idea of re-implanting them one day should the patients wish to have children. Of 167 eggs, 41 were successfully matured, some of them from the prepubescent donors. The young eggs were indistinguishable from those of older women.

Research outcomes will be slow coming and won't reveal themselves until the young girls might be ready to have children.

"We will only know the final chapter of this story in about 10 years, when we hope to close the circle of this research," Revel said.

Concerns about using this procedure include the invasive operation it requires as well as ethical concerns.