Could egg defect breakthrough help stop the ‘horrible IVF rollercoaster’? | IVF

It’s a rollercoaster of emotional extremes that will be familiar to many who have undergone IVF treatment: hope and joy turn to despair and vice versa. This is particularly true for women over 35, an age where IVF success rates decline sharply and for whom the only real way to improve their chances is to keep trying.

Although tremendous progress has been made in IVF in recent decades, including the advent of genetic testing, egg freezing and techniques to overcome male infertility, the primary cause of age-related female infertility – egg quality – has not been directly addressed.

Now, groundbreaking research presented this week at Fertility 2026 in Edinburgh suggests progress is on the horizon. Scientists at a leading German laboratory say they have successfully reversed a common age-related egg defect, thanks to a breakthrough they say could be transformative.

“Currently, there is no method to improve egg aging. This is a very large unmet need,” said Dr. Agata Zielinska, co-CEO of Ovo Labs and one of the scientists behind this breakthrough. “This would be a first-rate solution to improve egg quality.”

Eggs are particularly vulnerable to aging because women are born with all their eggs. Sperm, on the other hand, is generated continuously from stem cells present in the testes throughout adult life.

When undergoing IVF treatment, women under 35 had an average birth rate for each embryo transferred of 35%, compared to just 5% for women aged 43 to 44, according to the most recent figures from UK clinics. And it’s the age of the egg, not the woman, that matters most. When older women use eggs from younger donors or their own frozen eggs, the success rate is almost entirely defined by the age of the egg.

“The female eggs stay there for a very long time,” said Dr Güneş Taylor, who studies female fertility at the University of Edinburgh. “It’s been quite difficult to figure out what’s wrong with them. They’re supposed to stay dormant.”

A key part of this puzzle appears to have been solved by scientists working in the laboratory of Professor Melina Schuh, director of the Max Planck Institute for Multidisciplinary Sciences in Göttingen and co-founder of Ovo Labs.

They found that as eggs age, they contain less of an essential protein, called Shugoshin 1, which acts like glue to keep the egg’s chromosomes stuck together in X-shaped pairs. Without enough of this adhesive, the chromosomes begin to fray. This means that the pairs of chromosomes will not divide equally when the egg is fertilized, resulting in a higher rate of embryos with an incorrect number of chromosomes.

Often these embryos begin to develop normally, but are ultimately not viable. For IVF patients, this can create an initial feeling of hope that is destined to turn into disappointment.

“The strange thing about humans is that without the normal number of chromosomes, you can still go a long way,” Taylor said. “That’s how you end up with this horrible IVF roller coaster when you seem to get pregnant and the cycle fails.”

The latest work provides tantalizing evidence that a significant age-related egg defect could be reversible. In the results presented in Edinburgh, they showed that eggs supplemented with Shugoshin 1 were almost half as likely to have a chromosomal defect. This suggests that there may be a window of opportunity in IVF treatment between egg harvest and fertilization, during which the eggs could receive a rejuvenating microinjection.

“Our goal is to really reduce the time it takes for a successful design,” Zielinska said. “Many more women would be able to conceive in a single IVF attempt.”

The research is still in the experimental stage and will require years of additional testing. And, in an area known for exaggerating the costs of IVF add-ons, patients are right to reserve judgment. Ovo Labs has yet to prove that the proposed technique is safe and that the apparent improvements in egg quality translate into a real difference in IVF rates. The team did not want to put a time frame on how long this might take when asked whether it could be a few years, five years or a decade.

“We don’t want to overpromise,” Schuh said.

It is hoped, however, that this progress could be a step towards tackling one of the main causes of female infertility – and the reason why the IVF journey is so often so painful.

“While we await further details and confirmatory clinical trials, including addressing safety issues, these findings have great potential to improve IVF success rates,” said Professor Richard Anderson, head of obstetrics and gynecology at the University of Edinburgh, who was not involved in the work.

“We all have friends who have struggled with IVF,” Schuh said. “It’s a long journey and such an emotional burden. I really hope we can make this whole experience more successful.”