Becoming a mother at 50 could become the norm within the next decade, say scientists who have successfully “reversed the aging” of human eggs.
In a major breakthrough, Israeli researchers have actually made the eggs of 40-year-old women look like those of 20-year-olds.
Women are born with all their eggs, but their condition deteriorates over time, making it harder for older eggs to fertilize.
While the average woman in her 20s has an 80 percent chance of getting pregnant naturally within a year, by age 40, that rate is halved. Only a few hundred women in the UK become mothers at the age of 50 each year.
But scientists at the Hebrew University of Jerusalem have shown that deterioration can be reversed with an antiviral drug used to treat patients with HIV.
It is thought to work by preventing DNA damage that occurs during the aging process with a drug that blocks genetic damage during viral infections.
Questions still remain as to whether this process can increase fertility rates because the study did not expose processed eggs to sperm.
But now the team plans to test it in animals and then eventually in humans. There is also hope that the treatment may reduce the risk of miscarriages and birth defects, which are more common in older mothers.
Scientists from the Hebrew University of Jerusalem treated human embryos with an antiviral drug and found that it corrects many genetic errors, making them look like the embryos of a 20-year-old woman (photo)
What are the chances of getting pregnant later in life?
Women are born with all the eggs, but over time they deteriorate.
This makes it harder for older women to get pregnant.
The following are the estimated chances of getting pregnant naturally:
- in the early 20s and late 20s, 80 percent;
- Early 30s, about 70 percent;
- In the late 30s – about 60%;
- Early 40s, 20 to 40 percent.
More than eight out of ten couples with a woman under 40 will conceive naturally, according to charities.
But in some cases, they will need to turn to fertility treatment to improve their chances of getting pregnant.
This includes IVF, where an egg is fertilized in a test tube and then implanted into a patient.
Below are the chances of getting pregnant for an IVF round based on age.
- from 35 to 37 years old – 23%;
- from 38 to 39 years old – 15%;
- from 40 to 42 years – nine percent;
- from 43 to 44 years old – 3%;
- Over 44, two percent.
The NHS generally offers three cycles of IVF for women under 40, although this treatment is not available in some areas.
He can also offer one IVF cycle to women aged 40 to 42.
As an egg ages, parts of its DNA can begin to attack other areas, much like viruses can replicate.
To stop this, scientists have suggested that an antiviral drug called a reverse transcriptase inhibitor, used to prevent DNA damage in viral infections, might help.
Dr. Michael Klustein, the molecular biologist who led the study, told the Times of Israel: “Many women are trying to get pregnant in their 40s and older, and we think it can actually increase their fertility levels.
“Within 10 years, we hope to use antivirals to increase the fertility of older women.
“It can help women in their 40s and 50s. After that, we have menopause.”
He added: “Because the attacking DNA behaves like a virus, we hypothesized that an antiviral drug applied to eggs could reverse aging and rejuvenate them, and in our lab we found this to be the case.”
“We tested hundreds of mouse eggs and then human eggs, which confirmed the hypothesis.”
Boasting about the results in a press release, the team said that the old mouse eggs that had been processed “returned to their former youthful state.”
First, the drug was tested on hundreds of mouse embryos, and then was used on human embryos left after IVF procedures.
Scientists emphasize that they have not yet tested the introduction of sperm into processed eggs, so they have not proven whether this increases fertility.
Women are now giving birth later than ever in the West.
In the UK, the average age of first mothers is now 29 – up from 23 in the 1970s – with many postponing having children until the age of 30.
In the US, it has grown from 21 to 26 years old.
This change is thought to be due to more women prioritizing their careers, as well as changes in society and financial issues.
But the chances of getting pregnant decrease as a woman ages.
Studies show that it is only five percent when a woman is over 40 years old.
To get around this, many women now freeze their eggs when they are younger in preparation for fertility treatment later in life.
Every year in the UK about 50,000 women seek fertility treatment, and in the US more than 90,000.
IVF treatment success rates are about 25 percent – or one in four embryos – for women aged 35 to 37. For those under 35, the rates are around 32 percent.
The study was published in the journal Aging Cell.