Nat and Nik Fraser-Edwards celebrated their son Jude's first birthday last month.
After rounds of failed fertility treatment, Jude was a dream come true for the couple who said they hoped to give him a brother or sister next year. But now their dreams have come "crashing down".
Their sperm donor has withdrawn his consent for further use, and the remaining five embryos in storage will be destroyed after paying £23,000 on fertility treatment.
In the UK, a sperm or egg donor can withdraw consent up until the embryo is transferred into the womb.
The couple now want the law changed so that once an embryo has been created, consent cannot be withdrawn.
The UK government said it sympathised and added it is "keeping all aspects of the regulatory regime under review".
When they returned from their honeymoon in 2023, the couple from north Wales started fertility treatment.
They took out loans and went through rounds of failed fertility treatment in a journey that cost them a total of £23,000.
"There was a lot of pain during that time, and everyone around us seemed to be getting pregnant," recalled Nat, 37.
"All you see is babies. It's not just wanting that baby so much, it's the cancelled plans in case you get that smiley face."
It was only when they turned to a different type of treatment, called ICSI , where the egg is fertilised with sperm and the embryo is created outside of the body, that they had success.
Nat and Nik ended up with six embryos and in August last year, Jude was born.
The embryos were put into storage until the couple were ready to grow their family.
It was during a telephone consultation in June that they found out their embryos would be destroyed.
"It was very much, 'unfortunately your donor has withdrawn his consent to use your embryos'," said Nat, who lives in Penyffordd, near Wrexham.
"They said, 'we keep them for a cooling off period of a year and' - I think the hardest word for us was - 'we then allow them to perish'.
"We were absolutely floored."
Nik said the couple felt "blindsided" by the fact that their sperm donor could withdraw consent at that stage.
"Yes, we'd signed something," she added. "But we didn't ever recall it being verbally said."
The number of donors in the UK that withdraw consent is unknown as the data isn't collected. While it is rare, it is not unheard of.
Sam Beesley and Carly Estlick are expecting their first child, a boy they plan to call Finn, in October after going through IVF.
"I've been someone who knew from a young age that my job in life was to be a mother," said Sam, 41.
Just like Nat and Nik, Sam and Carly were told last month that their sperm donor had withdrawn consent and their 10 remaining embryos will be destroyed next year.
"When we got the letter saying he had withdrawn consent, it felt like the wind was taken out of our sails," said Sam from Shrewsbury.
"We had been so focussed on the pregnancy and something going wrong, I don't think it's really sunk in yet.
"Carly is already grieving. In her head, they've already been destroyed. Whereas until that day in 2027, I will not stop fighting."
Sam said the news has put pressure on their current pregnancy.
"Carly is very fearful that something will happen to Finn," she said. "It has crossed my mind.
"I did have some reduced movements the other day and had to go to hospital. You can't help thinking, is this going to be ripped away from us as well?
"This is probably our only shot at being parents. I don't know how we could afford to go through it again financially, emotionally, physically."
For both couples, fertility treatment has had an emotional and financial impact.
The UK fertility regulator HFEA has said that any change in the law on sperm donation is down to the UK government.
"It's about each person who provides an egg or sperm having that autonomy to consent and make that decision to whether they're happy for a child to be born in treatment," said Rachel Cutting, HFEA's director of compliance.
"Once the embryos in the uterus, in the woman's womb, there can't be a withdrawal of consent for that.
"The way that the law is written is that consent can be withdrawn from up to that point.
"We can look at it further, but it is for the law to be changed and that's not something within the power that the HFEA has. We can't change the law. But we are sympathetic to cases like this."
The HFEA has said it is important that clinics warn patients of the possibility of donors withdrawing consent "because it is really upsetting and distressing when this happens".
The UK government said it also sympathises with "anyone facing difficult and distressing circumstances during fertility treatment."
A Department of Health and Social Care spokesperson said: "We continue to work closely with the fertility sector to support high-quality, compassionate care, and we keep all aspects of the regulatory regime under review to the same end."
If you or someone you know has been affected by the issues raised in this story, information about available help and support can be found viaBBC Action Line.
