Women could be mothers at 50 after ageing of eggs is reversed

Scientists say treatment with antiviral drugs makes chromosomes younger and could improve fertility

MOTHERHOOD could be extended well into middle age after Israeli scientists successfully made eggs from 40-year-old women resemble those of 20-year-olds.

Women are born with all their eggs, but they degrade over time, so while the average 20-year-old has about an 86 per cent chance of getting pregnant, it falls to 36 per cent for a 40-year-old.

But researchers at Hebrew University, Jerusalem, have shown that treating eggs with an antiviral medication can “reverse age” older eggs, so they have chromosomes that look more like those from younger eggs, with less damaged DNA.

Although the team is yet to show it improves fertility, they hope to move to animal trials soon, and eventually, to humans. The breakthrough could not only help older women become mothers, but could potentially prevent miscarriages and congenital defects, which are more common with age.

“Many women are trying to get pregnant aged 40 or over, and we think this could actually increase their level of fertility,” Dr Michael Klutstein, a molecular biologist who led the research, told The Times of Israel. “Within 10 years, we hope to use antiviral drugs to increase fertility among older women. This may help women between the ages of 40 and 50. After that, we hit menopause.”

The team singled out a part of the ageing process that prevents the successful maturation of an egg cell. As a woman ages, her own DNA can start to damage the DNA in egg cells in a similar way to how a virus attacks, making copies of themselves inside the cell.

When young, the body can mount a response against this but it becomes weakened with age.

Dr Klutstein, added: “Because the attacking DNA behaves like a virus, we hypothesised that antiviral medicine administered to eggs may reverse age them and rejuvenate them, and found in our lab that this is the case.

“We tested hundreds of mouse eggs and then human eggs, which confirmed the hypothesis.”

The team used a class of antivirals called reverse-transcriptase inhibitors which are used to treat viruses such as HIV and HPV and which prevent DNA damage in the eggs.

The technique was trialled in hundreds of mice eggs as well as human eggs that had been left over from IVF cycles and donated to science. The research was published in