Babies could be born without any biological mother after scientists make major breakthrough
Warning: This article contains discussion of baby loss which some readers may find distressing.
A revolutionary new fertility treatment could allow women who no longer have their own eggs - either because of age or cancer treatment - to have children.
The scientific breakthrough, while still in its early stages, could also mean that gay male couples could have a child that is genetically related to both of them - effectively born without a biological mother.
Experts say the finding could one day 'transform' the understanding of infertility and miscarriage, and even pave the way for creating egg or sperm-like cells for people who have no other options.
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In some cases, infertility can be caused by the body’s inability to produce healthy sperm or eggs and treatments such as IVF are ineffective for these patients unless a donor is used.
But, an emerging process, known as in vitro gametogenesis (IVG), involves reprogramming skin cells to become a type of stem cell - something which researchers say has 'immense therapeutic potential' for people who have no viable eggs or sperm.
How does IVG work?
In short, American researchers demonstrated it was possible to replace the DNA from an egg with the genetic material from another person’s skin cells, and turn it into a sex cell ready for fertilisation.
The process involves taking the nucleus, which is the control centre of the cell which stores its genetic material, from a patient’s own skin cells.
These are then implanted into a donor egg with its nucleus removed in a process known as somatic cell nuclear transfer.
However, cells generated in this way would cause any future fertilised egg to have too many chromosomes.
Humans typically have 46 chromosomes, organised into 23 pairs – half from the sperm and half from the egg.
Cells created using somatic cell nuclear transfer have two sets of chromosomes.
A method to remove this extra set of chromosomes has been studied in mice, but has never been used on human cells.
To combat this, researchers in the US removed the nucleus from skin cells and implanted it in a donor egg.
To remove the extra chromosomes, they carried out a process they have called mitomeiosis.
This mimics natural cell division that causes one set of chromosomes to be discarded, leaving behind a healthy reproductive cell capable of being fertilised.
The team was able to create 82 functional developing eggs known as oocytes, which were fertilised using sperm in a lab.
Almost one in 10 (nine percent) of the fertilised eggs went on to develop to the blastocyst stage, which is when cells rapidly divide around six days after fertilisation.
No blastocysts were developed beyond this point, which coincides with the time they would usually be transferred to the uterus in IVF treatment.
What couples can IVG help?
Well, the major breakthrough opens up the possibility of skin DNA from a man being placed inside a donor egg and fertilised by another man, leading to a baby with two biological fathers and no DNA from a woman.
Additionally, it could also provide an unlimited supply of fresh eggs for women who struggle to conceive because of age, infertility or medical treatment.
'It could transform how we understand infertility'
Dr Paula Amato, a professor in obstetrics and gynaecology at Oregon Health and Science University, told The Telegraph: "In theory, the technique could result in a limitless number of eggs.
"The skin cell DNA however, can come from anyone, even if they personally don’t have any eggs or remaining eggs – older women, women after cancer treatment, people born without eggs, men...
"So, it’s a way to produce eggs genetically identical to the person providing the skin cell, even if they personally don’t have any eggs, and allows them to reproduce to have a genetically-related child.
"A same-sex male couple could potentially have a child genetically related to both partners."
UK experts have also expressed excitement at the finding but outlined that further work is needed.
Ying Cheong, a professor of reproductive medicine and honorary consultant in reproductive medicine and surgery at the University of Southampton, said: "For the first time, scientists have shown that DNA from ordinary body cells can be placed into an egg, activated, and made to halve its chromosomes, mimicking the special steps that normally create eggs and sperm.
"This breakthrough, called mitomeiosis, is an exciting proof of concept.
"In practice, clinicians are seeing more and more people who cannot use their own eggs, often because of age or medical conditions."
He continued: "While this is still very early laboratory work, in the future it could transform how we understand infertility and miscarriage, and perhaps one day open the door to creating egg- or sperm-like cells for those who have no other options."
Meanwhile, Professor Richard Anderson, Elsie Inglis professor of clinical reproductive science and deputy director of the MRC Centre for Reproductive Health at the University of Edinburgh, added: "Many women are unable to have a family because they have lost their eggs, which can occur for a range of reasons, including after cancer treatment.
"The ability to generate new eggs would be a major advance, and this study shows that the genetic material from skin cells can be used to generate an egg-like cell with the right number of chromosomes to be fertilised and develop into an early embryo.
"There will be very important safety concerns, but this study is a step towards helping many women have their own genetic children."
If you need support and advice following a pregnancy loss, you can contact the Tommy’s team at [email protected]. You can also call them for free on 0800 014 7800, Monday to Friday, 9am to 5pm.
Topics: Health, News, Parenting, Pregnancy, Science, Technology, Women's Health, World News, LGBTQ,
Rhiannon Ingle