'Older eggs may be made suitable for IVF': Mouse study

 As women age, the quality of their eggs decreases and they become less useful for in vitro fertilization. But it may someday be possible to "rejuvenate" older eggs to improve the likelihood of successful pregnancies and healthy babies, a study in mice suggests.

In the ovaries, immature eggs are housed in fluid-filled sacs called follicles. When an egg matures, the follicle ruptures and releases the egg during ovulation.

It seems, Haiyang Wang and colleagues at the National University of Singapore reported in Nature Aging, that moving "aged" eggs into "younger" follicles can partially restore their reproductive function, and in turn, generate eggs that are of better quality for in vitro fertilization.

In experiments in mice, the researchers extracted healthy follicles from young animals and cultured them in test tubes. Then they extracted older eggs from their original follicles and transplanted them into the younger follicles, whose own eggs had been removed.

The results showed that "the quality and developmental competence of the aged (egg) can be substantially, though not fully, restored through 'nurturing' in a young follicular environment," the researchers said in a statement.

There were improvements seen in the aged eggs' metabolism, gene expression and energy production. There was also evidence that the young follicular environment could support processes that reduced the number of abnormal chromosomes.

In the mice, "All these improvements enhance the success of embryonic development after in vitro fertilization, leading to a live-birth rate around three times higher than that achieved with aged oocytes not exposed to the young follicular environment," the researchers said.

Of course, more research is needed to know whether these findings can be extended to humans.

Women starting at around age 42 to 45 are typically advised not to proceed with IVF with their own eggs because older eggs have a higher chance of abnormalities.

https://www.yahoo.com/news/health-rounds-older-eggs-may-205220049.html