The success rates of in vitro fertilization (IVF) are contingent upon a few different things, but perhaps mostly on a woman’s age. Even with perfectly young eggs IVF can be extremely difficult. But new research published in the Journal of Endocrinology found harvesting eggs during early stages of treatment may improve pregnancy outcomes for older women.

Researchers from The Center for Human Reproduction in New York compared the granulosa cell (GC) function in younger donors (aged 21-29), middle-aged donors (aged 30-37), and older infertile patients (aged 43-47). GCs, sometimes referred to as follicular cells, are what envelop and support the eggs inside the ovary to help them grow. And what researchers found was that granulosa cells were significantly less likely to grow in older women compared to the other two groups.

“These observations demonstrate age-related functional declines in GCs, consistent with premature luteinization,” the team reported in their study.

Luteinization is what stops the ovaries from maturing more eggs and better priming the uterus for pregnancy. And in the GCs of older women, researchers found there were more luteinizing hormones than follicle-stimulating hormones. The younger donors only showed a “marginal increase” in these inhibiting hormones.

So even though eggs in younger donors were harvested earlier compared to other donors, they went on to produce a higher number of quality embryos, thus IVF success rates were higher compared to women complying with standard fertility treatment.

"We used to think that aging eggs were responsible for poor IVF success rates in older women, but here we show that it is more due to the aging of the egg's environment," study author Dr. Yanguang Wu, embyrologist and associate scientist at the Centre for Reproductive Medicine, said in a press release. "The chances of reversing damage to an egg are practically zero, and so these findings are exciting because it's much more hopeful to therapeutically target the egg's supporting environment."

Yanguang admitted more research needs to be done, namely larger-scale studies with more patients, but as is, these results offer "insight into ovarian aging, and we hope this will help produce new strategies for improving pregnancy outcomes in older women."

Source: Yanguang W, et al. Retrieving eggs earlier in fertility treatment may improve IVF success rates for older women. Journal of Endocrinology. 2015.