In January 2026, scientists announced they discovered why eggs age and found potential ways to reverse the process. These breakthroughs could improve success rates for In Vitro Fertilization (IVF), which is a procedure where eggs are fertilized in a laboratory. The findings could also lower the risk of health problems that occur as eggs age.

Two separate teams of researchers led the studies: one from the Max Planck Institute in Germany and another from Yale University. Both groups focused on restoring specific proteins that help prevent genetic mistakes when cells divide.

Reducing Genetic Defects

One study focused on a protein called Shugoshin 1. Prof. Melina Schuh and Dr. Agata Zielinska presented their findings at the British Fertility Conference in Edinburgh. They explained that levels of this protein naturally drop as women get older. This loss is a major cause of fertility problems because the protein acts like a glue for chromosome pairs, which are the structures that carry DNA.

In laboratory tests, researchers injected Shugoshin 1 into eggs donated by patients at the Bourn Hall fertility clinic in Cambridge. According to the study, the injections nearly halved genetic errors across the entire study group, with defects dropping from 53% to 29%.

Researchers saw a similar trend in eggs from women over age 35, where defects dropped from 65% to 44%. However, the team cautioned that because the study was so small, the results for that specific older group might have happened by chance.

Monitoring the Aging Process

A separate study investigated how a protein called REC8 breaks down over time. Assistant Professor Binyam Mogessie and his Yale University team used gene-editing and time-lapse photos to watch the aging process in mouse eggs.

The study, published in the journal Nature Aging on January 9, 2026, identified the exact point where protein loss makes DNA more likely to split incorrectly. Researchers noted that the techniques developed during this study could eventually help give women about three more years to safely get pregnant.

Changing Trends and Limitations

This news comes as more women choose to have children later in life. In the United Kingdom, for example, data shows that about 35% of IVF procedures for women under age 35 result in a birth. That rate falls to just 5% for women aged 43 to 44. Similar trends are occurring in the United States, where births to women under 30 are decreasing while births to women over 30 are on the rise.

While the research shows promise, scientists noted that the treatment cannot extend fertility forever. The technique aims to refresh existing eggs, but it cannot create new ones or stop the body from naturally running out of eggs—the process that leads to menopause.

Ovo Labs, a startup co-founded by Prof. Schuh and Dr. Zielinska, is now working to turn the protein injection into a treatment. The company is working with health agencies to begin clinical trials, which test new treatments using human volunteers.