Sperm donor cancer risk is at the centre of a Danish scandal involving the European Sperm Bank, after sperm from a single donor carrying a mutation in the TP53 gene was distributed to clinics in 14 countries over almost two decades. At least 197 children have been born with the donor’s sperm, and health authorities across Europe are now trying to trace families so that children who may carry the mutation can be offered genetic testing and long-term cancer screening.
The case, revealed by a cross-border investigation led by Danish public broadcasters and partners in the EBU Investigative Journalism Network, raises questions about how one donor could be used so widely despite national limits on donor use, and why there is still no common European ceiling on donor offspring.
A sperm donor cancer risk with European consequences
The donor, identified publicly only by the alias “Kjeld” and the number 7069, began donating in Denmark in the mid-2000s. According to documents from health authorities cited by Danish media, sperm from this donor was sent to 67 fertility clinics in 14 European countries between 2006 and 2022.
In Denmark, clinics used the sperm to help conceive 99 children, about half of whom are Danish. In Belgium, the same donor’s sperm led to 53 children being born, even though Belgian rules state that sperm from one donor should be used for a maximum of six women.
Other affected countries include Sweden, Spain, Iceland and several other European states, where national authorities are now trying to count how many children may be biologically related to the Danish donor. Because there is no joint European register of donor-conceived children, the numbers outside Denmark are still incomplete.
The TP53 mutation and a rare inherited cancer syndrome
The cancer risk in this case is linked to a mutation in TP53, a gene that plays a crucial role in repairing DNA damage and preventing cells from becoming cancerous. Certain mutations in TP53 are associated with Li-Fraumeni syndrome, a rare inherited condition that gives carriers a very high lifetime risk of developing multiple forms of cancer, often from childhood.
In this case, the donor himself is reported to be healthy and unaware of the mutation. Testing later showed that only some of his sperm cells carry the TP53 variant, meaning not all donor-conceived children will have inherited it. However, for those who did, the mutation can significantly increase the risk of early-onset cancers, including leukaemia, brain tumours and soft-tissue sarcomas.
Oncologists and genetic counsellors recommend that children who test positive for such a mutation are enrolled in intensive surveillance programmes, which can include regular whole-body MRI scans and other preventive checks. For families who turned to donor sperm as a route to parenthood, the discovery that their children may live with a lifelong cancer risk has brought a heavy emotional and practical burden.
How regulatory gaps allowed one donor to reach 197 children
Danish authorities say the European Sperm Bank stopped using the donor’s sperm around 2023, after the TP53 mutation was identified in his samples and the risk confirmed. By then, however, the donor’s sperm had already been used in large numbers of treatments in Denmark and abroad.
The scale of the case highlights structural weaknesses in both national rules and cross-border regulation. For years, Danish guidelines advised clinics to ensure that a donor did not father more than 25 children in Denmark. In 2013, Denmark introduced a legal limit of 12 families per donor.
But there has never been a shared European limit on the total number of children or families per donor across borders. Fertility clinics and sperm banks are required to follow national caps, yet they can sell sperm from the same donor in several countries, as long as each country’s domestic rules are respected. With no common register or real-time data sharing between states, regulators have limited tools to detect when the overall number of children per donor becomes very high.
Legal experts in Denmark describe the case as evidence of a “systemic breakdown” in the way clinics and banks report pregnancies and births. In practice, incomplete reporting from clinics, different legal definitions and fragmented IT systems made it difficult to monitor how often each donor was used.
Fertility tourism, missing data and fragmented oversight
The scandal also shines a light on fertility tourism. Denmark is a major hub for donor sperm, and many families from other European countries travel to Danish clinics for treatment, instead of importing sperm to their home country.
When patients cross borders, national registers in their home states may not record the birth as linked to a specific donor in another country. The result is that donor offspring are scattered across multiple registries, some of which do not systematically track donor-conceived children at all.
This fragmentation makes it harder to alert families when a serious health risk is discovered. Health authorities and investigators now have to reconstruct the donor’s history clinic by clinic, country by country, to find families who may never have been told that their child was conceived with this specific donor.
The case also exposes differences in data protection and transparency. Some countries maintain or are setting up national donor registries, while others rely on clinics and private banks to keep their own records. For donor-conceived people trying to understand their genetic background, or for regulators who need to respond quickly to health alerts, this patchwork of rules is a major obstacle.
European Sperm Bank under scrutiny
The European Sperm Bank, one of the largest private sperm banks in the world, has declined interviews with several media outlets but provided written answers. The company acknowledges that the limits on the number of families per donor have been exceeded in some countries, including in the TP53 case.
In its response, the bank points to a combination of factors: incomplete reporting from clinics, IT systems that were not robust enough and the effects of fertility tourism, where treatments take place in other jurisdictions. The company says it is now in dialogue with authorities in Denmark and Belgium to strengthen monitoring and ensure that national limits are observed in the future.
The sperm bank also stresses that all donors are medically assessed and genetically screened in line with current scientific standards and legal requirements. However, experts note that this case suggests that current screening protocols and reporting mechanisms may not be sufficient when donors are used across many countries over long periods of time.
Nordic and EU debate on donor limits and genetic screening
The Danish case comes at a moment when Nordic and EU policymakers are already debating how to tighten rules around sperm and egg donation. Several European countries have national laws that cap the number of children or families per donor, but there is still no binding European limit on the total number of offspring when donations cross borders.
In response to earlier revelations about cancer-linked donor sperm, health ministers from Sweden, Belgium and other EU countries have called for international limits on donor offspring and a cross-border donor register. They argue that without shared data, it is impossible to guarantee that donors are not used at a scale that raises ethical, psychological and health concerns for donor-conceived people.
At the same time, the European Union has adopted a new Regulation on substances of human origin (SoHO), which will apply from 2027 and cover, among others, donated sperm and oocytes. The regulation aims to harmonise safety and quality standards for donors, recipients and children born through medically assisted reproduction, and to improve the way serious adverse events are reported across member states.
However, experts point out that even the new framework will still rely on national limits for donor use and does not in itself impose a single European cap on the number of children per donor. Unless member states agree on common numerical limits and shared registries, they warn, cases like the Danish TP53 donor could be repeated.
What the scandal means for families and for Europe
For families who used donor sperm in the hope of starting or expanding a family, the discovery of a cancer-related mutation in the donor’s sperm raises difficult questions. Some children will test negative and can be reassured. Others will live with a confirmed, elevated lifetime risk of cancer and ongoing medical surveillance.
For Nordic and European policymakers, the case has become a concrete example of how cross-border reproductive markets can outpace the rules designed to keep patients and children safe. It is likely to fuel calls for stronger EU-wide coordination, better tracking of donor-conceived children and clearer responsibilities for private sperm banks and clinics.
Whether this scandal leads to stricter European donor limits and more transparent registries will depend on political choices in the coming years. For now, the priority for health authorities is to identify and inform all affected families, so that children who may have inherited the TP53 mutation can be tested and monitored as early as possible.
