EU weighs sperm donor cap to curb risk of accidental incest

Sweden and Belgium want to discuss an EU limit on the number of children conceived from a single sperm donor — to prevent future generations from unwitting incest and psychological harms.

Donor-conceived births are rising across Europe as fertility rates decline and assisted reproduction becomes more widely accessible — including for same-sex couples and single women. But with many countries struggling to recruit enough local donors, commercial cryobanks are increasingly shipping reproductive cells known as gametes — sperm or egg — across borders, sometimes from the same donor to multiple countries.

Most EU countries have national limits on how many children can be conceived from one donor — ranging from one in Cyprus to 10 in France, Greece, Italy and Poland. However, there is no limit for cross-border donations, increasing the risk of potential health problems linked to a single donor, as well as a psychological impact on children who discover they have dozens or even hundreds of half-siblings. 

Sweden, backed by Belgium, is raising the topic with EU ministers on Friday, with hopes of preventing future generations from dating half-siblings and reducing risk of heritable diseases. “This issue has been left unresolved for too long,” an official from Belgium ,granted anonymity to speak freely, told POLITICO, adding that an “international limit is a first step in the right direction.”

A limit would prevent high numbers of children conceived from the same donor, reducing risks of hereditary diseases and half-siblings unknowingly getting together. “We don’t want genetic half siblings to … start families,” Carolina Östgren, research officer at the Swedish National Council on Medical Ethics, told POLITICO. 

Sweden’s ethics council started looking into the issue in 2023, following an article published in newspaper Dagens Nyheter, which reported that Swedish clinics are selling donated sperm abroad resulting in one donor potentially fathering more than 50 children.

In Sweden, each donor can only provide donations to six couples. However, there are no restrictions on how many children a donor may father across different countries. And the clinics are using this to go beyond the national limits. 

Booming business, growing risks

Some cryobanks — sperm and egg banks — set their own voluntary limit for the maximum families or children per donor. The fertility clinic in the Dagens Nyheter article had a voluntary cap of 25 families worldwide per donor; however, while the donors were informed about the exports, many recipient parents didn’t know their children could have up to 50 half-siblings.

Most EU countries have national limits on how many children can be conceived from one donor. | Andreas Arnold/Picture Alliance via Getty Images

A recent case —  a donor with a rare cancer-causing gene whose sperm was used to conceive at least 67 children, 10 of whom have since been diagnosed with cancer — “is another example of why we have to regulate this on an international level,” Östgren said. 

A spokesperson for the European Sperm Bank, one of the bloc’s largest cryobanks providing sperm and egg donations to 80 countries, told POLITICO that donors go through extensive health checks and family history reviews. From a medical perspective, choosing a donor is generally safer than conceiving naturally, the spokesperson argued. However, those screenings would not have detected the cancer-causing TP53 gene mutation that was carried by the donor. 

“You can never be 100% sure of detecting everything,” Peter Reeslev, head of Denmark-based Fertility Consultancy, which provides international advice to fertility clinics, said in a written response. “Centralised registry can support and limit donor number of offspring, but imagining no illnesses will occur among donor conceived children is naïve.”

“We can’t do whole-genome sequencing for all sperm donors — I’m not arguing for that,” Edwige Kasper, a biologist at Rouen University Hospital in France, who presented the cancer-risk donor case at the annual conference of the European Society of Human Genetics in Milan told The Guardian. “But this is the abnormal dissemination of genetic disease. Not every man has 75 children across Europe.” On average a European man has one to two children. But through donations, the number can rise as high as 550 children, as in the case of a Dutch sperm donor who has been banned from further donations.

Mind the cap!

Cryobanks warn that overly strict limits could reduce supply, which is already running short. The European Sperm Bank argued that only 3-5 percent of men who begin the selection process are approved, warning that if family limits are set too low this would drive up screening costs and wait times, potentially pricing out would-be parents.

Cryobanks use one donor for conceiving as many children as possible, because the unit cost is lower, Östgren said. The European Sperm Bank caps the number of would-be parents that can use one donor at 75, allowing one donor to potentially father hundreds of children.

Its price for a single-use sperm vial varies from around €700 to €1,100. But this bank also offers prospective parents the chance to opt for an exclusive donor — meaning no other families will ever receive their sperm. But it comes at a cost. Screening fees would be distributed across fewer families which would increase the price, the European Sperm Bank said in written response, without giving a value. 

But that logic doesn’t fly with ethicists. “You cannot say that it’s cheaper, and that’s why we should do it,” Östgren said. “We must think of other factors than the business logic here.”

The concerns also go beyond hereditary health risks and possible incest. Thanks to the rise of consumer DNA testing and social media, donor-conceived individuals are now discovering dozens — sometimes hundreds — of genetic half-siblings worldwide. 

“The psychological impact of discovering that you have dozens of half-brothers and sisters in Europe or even the wider world carries a huge impact,” the Belgian official said. “The world is getting smaller and smaller. People look for each other, find each other faster.”

Fertility consultant Reeslev agreed that “due to changes in communicational platforms and transparency e.g. DNA testing, the time has come for a sperm donor limit on a European level.”

In some countries, the donor’s identity is kept secret unless the child experiences severe health conditions. Other countries allow donor-conceived children to know who the donor is from a certain age, ranging from 15 to 18 years. Some, such as Denmark, allow the donor to choose whether to be anonymous or open. 

Belgium wants to erase the anonymity option. “We also advocate (for) a European central donor register and support the removal of anonymity,” the official said. “This is about the right of the child to know their parentage.”

The case for EU action

To raise attention of the issues in March this year Sweden, together with ethics councils from Norway, Finland and Denmark, published a joint report, calling for the EU discuss issues around international donations. 

Donor-conceived births are rising across Europe as fertility rates decline and assisted reproduction becomes more widely accessible. | Lee Sanders/EPA

Their call has been heard. 

“We’re really happy that they are taking this seriously and discussing it on the broader level, on the European level,” Östgren said. 

The European Sperm Bank is also hoping the ministerial discussion will lead to a harmonized cap on the number of families per donor and the establishment of a central EU donor registry to ensure long-term traceability and secure access to vital donor information. 

That’s because the EU’s new regulation on substances of human origin, which will apply from 2027, while a step toward harmonizing currently widely varying rules and standards, doesn’t introduce a bloc-wide family limit and central donor registry.

In the meantime Östgren believes an EU decision would be a first step toward worldwide guidance. “Sperm is exported … in the whole world,” Östgren said.