Of Mice And Eggs; New research could extend childbearing age.

Byline: Temma Ehrenfeld

One of the most painful losses many women who've been diagnosed with cancer have to endure is the inability to bear a child. Chemotherapy, after all, kills cells that grow, and growth is what the apparatus of reproduction is all about. Last week two research groups that had set out to tackle this problem published some startling insights in the journal Nature that may help all women extend their childbearing years.

The first study involved Sarah, a rhesus monkey at the Oregon National Primate Research Center. Scientists removed one of her ovaries and injected slices of it under the skin of her abdomen. Once there, the tissue did what nature designed it to do: it began releasing hormones that triggered the growth of tiny fluid-filled capsules, or follicles; soon, egg cells matured in the follicles. The scientists removed several eggs, fertilized them and implanted one in another monkey, who gave birth to a healthy baby.

What worked for monkeys may also work for humans. Indeed, frozen tissue taken from a cancer patient has already yielded an embryo, though the patient (who prefers to remain nameless) did not become pregnant. "It's just a matter of time," says her gynecologist, Kutluk Oktay of the Weill Medical College of Cornell University. "It'll work in a patient one day." The process may give women a way to have children other than by freezing an embryo or a fertilized egg (unfertilized ones don't keep well on ice). Even a prepubescent girl unlucky enough to have to endure chemotherapy need not give up on having children of her own. And down the road, healthy 45-year-olds may be giving birth to babies ...