Injection halves chromosome errors in older eggs
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- Ovo Labs researcher Agata Zielinska presented at the European Society of Human Reproduction and Embryology conference in London on July 6, showing that injecting eggs with shugoshin-1 mRNA cut premature chromosome separation from 53% in untreated eggs to 29% in treated ones — a near-halving of the error rate.
- The study drew on 111 spare, immature eggs from more than 30 women aged 22–43; in eggs from nine donors over 35, aneuploidy dropped from an average of 65% untreated to 44% treated, though the team attributed the lack of statistical significance to the small sample size.
- Zielinska's team identified that shugoshin-1, a protein that maintains the molecular glue holding chromosome pairs together during meiosis, is substantially lower in older mouse and human eggs, allowing chromosome pairs to separate prematurely and produce aneuploid eggs.
- Treated mouse eggs were successfully fertilized and produced healthy offspring with no observed side effects, leading researchers to conclude the approach does not disrupt embryo development, pregnancy health, or pup health.
- The therapy, dubbed EmbryoProtect, would require modifying standard IVF to use immature rather than mature eggs — a change Zielinska called fairly easy to implement — and the team is now working toward human clinical trials.
- Independent expert Marcos Iuri Roos Kulmann of Nilo Frantz Reproductive Medicine in Porto Alegre called the finding "a big deal," saying it is the first therapy to show clinical potential for correcting a major cause of IVF failure.
Why it matters: Aneuploidy already affects more than 65% of eggs in women's late 30s and is a primary driver of IVF failure and miscarriage in that group; if the EmbryoProtect approach holds up in larger human trials, it could meaningfully raise live-birth rates while costing a fraction of a standard IVF cycle and reducing the number of attempts older women need.
