When the woman’s phone began to ring one morning in June, she did not know that the news she would receive would hurtle her and her teenage daughter into a "tunnel" of medical appointments, tests — and fear.

On the other end of the line, she said, was the head of the fertility department at a Belgian clinic she had visited in 2011 to undergo fertility treatment, which at the time was not available to would-be single mothers in France. After her daughter was successfully conceived, she said, she had never heard from the clinic again.

The caller told her that the sperm donor she had used to conceive her daughter carried a rare genetic mutation of the TP53 gene, which suppresses cancerous growth. The mutation is linked to a heightened and lifelong risk of multiple cancers — many of which can develop at a very early age. The caller said her daughter had a 50% chance of inheriting the mutation, for which there is no cure or treatment. It was, she was told, "urgent" for her to screen her daughter for the mutation.

"It was a shock," said the woman, who asked to remain anonymous. "I didn’t understand anything."

She would soon learn that her daughter did indeed carry the genetic mutation.

In fact, after the mutation was detected in his samples, the donor had been permanently blocked in October 2023 by the European Sperm Bank (ESB), which had sold the sperm. Though the clinic maintains that it contacted the woman "as soon as possible," it told her she received the call a year and a half after the ESB discovered the mutation because it had migrated its computer system and initially lost her contact details.

Sperm donor 7069** **

Coordinated by the EBU Investigative Journalism Network, an investigation by DW and several other European public broadcasters reveals that, for more than 15 years, women in at least 14 countries in Europe and elsewhere were sold sperm from donor 7069.

The ESB exported donor 7069’s sperm to 67 fertility clinics in 14 countries Image: DW/EBU

From Iceland to Albania and beyond, at least 197 children were conceived with donor 7069’s sperm, the investigation shows. It is possible that the number is far higher — the ESB has yet to disclose the total number of children conceived with his sperm. And so doctors are unable to say whether all of them have even been tested at this point.

Thus, a rare and potentially fatal genetic mutation was sold to families across Europe.

Some of the donor-conceived children have already developed two different sorts of cancer; others "have already died," said Edwige Kasper, a biologist who specializes in genetic predispositions to cancer. She is counseling some of the affected families.

Legally, the sperm bank has the obligation to alert all fertility clinics to which it exported gametes of any genetic abnormalities that arise. The clinics, in turn, inform parents.

And yet DW and its partners have learned of several cases of families who were never officially informed that their children might be carriers.

‘A big frustration’

Dorte Kellermann, a single mother who lives in Denmark, said she learned about the case in November 2023 from another parent who had used the donor. She told DW and its partners that she had not been contacted by either the sperm bank or the fertility clinic she had used. And, she said, she was aware of other families — single mothers who had used the same donor, and who had connected via a private Facebook group. The former director of the clinic Kellermann had used said he could not comment on individual cases.

Though DW is unable to verify each of the Facebook group’s accounts, they are consistent with those of doctors and reports issued by health authorities across Europe.

Dr. Svetlana Lagercrantz, who specializes in hereditary cancers, told the Danish Broadcasting Corporation, one of DW’s partners in the investigation, that several of her patients in Sweden had never been contacted. She said they had only found out about the mutation through media reports. It was, she said, "a big frustration."

Svetlana Lagercrantz and other doctors say early cancer detection is essential to saving livesImage: DW/EBU

Indeed, it took a gathering of hereditary cancer experts in 2024 to realize the extent of the problem. Lagercrantz said a French colleague was talking about patients who had inherited the TP53 mutation from their sperm donor.

Suddenly, she said, doctors from across Europe realized that what they had assumed were singular cases were in fact all fathered by one single donor — spanning the continent and even beyond.

It left her "shaken."

Lifelong screening** **

Citing privacy concerns, the ESB has so far refused to provide the exact number of children conceived with donor 7069’s sperm.

The European Sperm Bank has refused to provide the exact number of donor 7069’s offspringImage: DW/EBU

"Since we don’t know how many women have children with the donor, you keep thinking: But is there one more child?" Lagercrantz said. For her and her colleagues, it is "hard to let go of that thought."

People who are found to carry the mutation have to undergo regular and lifelong checkups. As cancer is particularly rare in children, she said, symptoms may be overlooked or misinterpreted when doctors are not aware of the mutation.

"The earlier you detect the cancer, the better the chance you have to cure it," she said.

Warning signs as early as 2020** **

The ESB’s website resembles a dating site, allowing potential clients to browse donor profiles and — for an extra fee — hear audio interviews and view childhood photos. Clients can fork over almost €1,000 ($1,165) for a more comprehensive genetic test than the routine tests sperm is required to undergo in Denmark.

DW and its partners came across donor 7069’s online profile first listed as early as 2007: "Kjeld," a tall white man with light brown hair and brown eyes who was listed as an "M.S. Economy Student."

The first warning came in 2020, according to the ESB, when the bank received a notification that a child conceived with Kjeld’s sperm had been diagnosed as carrying the TP53 mutation. His sperm was placed under quarantine until further genetic testing.​ ​The results came back negative, as the rare mutation occurs only in some of the donor’s sperm cells. The donor himself showed no symptoms. And his sperm was returned to the market.

In 2023, the ESB was informed of another child carrying the TP53 mutation. A new round of testing found that the mutation was indeed present in a portion of the donor’s sperm. This prompted a permanent ban — and phone calls to parents across Europe.

No Europe-wide cap on donor offspring

Headquartered in Copenhagen, the ESB has emerged as a major player in the global fertility trade, claiming to export sperm to countries across Europe and as far away as Afghanistan and Bolivia. In 2023, the ESB, which is owned by the private investment firm Perwyn, made more than 60 million Danish kroners, or about €8 million, in profit, a significant increase from the 35 million Danish kroners that it had made the previous year.

Solo parent by choice

The business is a lucrative and rapidly growing one as more medical procedures become available and women opt to have children later in life, sometimes on their own or with same-sex partners.

In Germany, donors, who typically donate once a week for six to 18 months, receive €80 per donation, the head of a sperm bank told DW. Their sperm is then washed, analyzed and packaged in so-called straws, longish tubes that are frozen in liquid nitrogen. Each straw sells for €1,000. Becoming pregnant is an expensive and potentially protracted process: Though some women only need one or two tries, many might need 10 or more — and some never manage to conceive.

The fertility industry is governed by a patchwork of rules and regulations. Some countries place an age limit on treatments or only allow them for married heterosexual couples. Some allow procedures that are banned in other countries. Some allow anonymous donations of sperm and eggs, which others ban. German patients, for example, may travel to Spain for egg donations, which are illegal in their home country; same-sex couples from Poland may travel to Germany for treatments they are denied back home.

Some countries place legal limits on the number of children born from one single donor. Others, like Germany, do not, but banks tend to follow industry guidelines of 15 families per donor. Though the European Union passed new regulations on medically assisted reproduction and substances of human origin in 2024, these do not include an EU-wide cap on the number of children born to a single donor. There is currently no international database that tracks donors and prevents them from selling sperm to several banks.

Donor sperm undergoes medical tests, yet TP53 is not included in the routine testsImage: David Spears/Mary Evans/IMAGO

Potential donors undergo extensive medical tests, and only a single-digit percentage make the cut. The process does not include screening for rare genetic mutations such as TP53. Having invested heavily in a donor, sperm banks have an economic incentive to maximize profit by selling each donor’s sperm to several families. ​​

On its website, the ESB claims to have set a self-imposed cap on the number of families per donor: "The majority of our donors have a limit of 75 families, but in selected markets (the UK, Ireland, Australia and the Netherlands) we also offer donors with a worldwide limit of 25 families." For an extra fee, prospective buyers can limit the number of families; €39,000 buys exclusivity.

The research by DW and its partners shows that the at least 197 children conceived with donor 7069’s sperm clearly exceeded the ESB’s own stated polices, as well as national limits in some cases. In Belgium alone, 53 children were conceived using the donor’s sperm,​ ​despite national laws that set a limit of six women per donor. This has prompted investigations by Belgian authorities.

Northern Cyprus clinics offer babies by design

Confronted with the findings, the ESB wrote: "We are deeply affected by the case and the impact that the rare TP53 mutation has on a number of families, children and the donor. They have our deepest sympathy." The ESB "tests and performs an individual medical assessment of all donors in full compliance with recognized and scientific practice and legislation."

"Unfortunately," the ESB wrote in its statement, "we have identified that the limits for how many families a donor can be used for have been exceeded in some countries both in the specific case regarding TP53 and in other cases. This is partly due to inadequate reporting from the clinics, non-robust systems and fertility tourism."

In her laboratory in central Berlin, Ann-Kathrin Klym did a double take when she heard the number of children conceived with donor 7069’s sperm. It is, she said, "enormous." Klym heads the laboratory at the Berliner Samenbank, a sperm bank that, with its 10 employees, is a minor player compared with the ESB. Klym showed DW the bank’s storage room: big, bulky containers filled with liquid nitrogen, which freezes the sperm. When she removed a lid to show the small straws with frozen sperm housed in each, whitish-grey nitrogen gas swirled out of the tank.

Sperm is stored in liquid nitrogen. Image: DW/EBU

Klym said her bank limited donors to 15 families and asked them to sign a declaration that they had not sold sperm to another bank.

People conceived with donor sperm and their parents are calling for Europe-wide and indeed global caps on the number of children born to one donor. Spenderkinder, an association of donor-conceived children in Germany, told DW that it advocates for a global cap of six families per donor, as well as a global registry of donors. That would also make it easier to find and contact families in a timely manner should sperm banks become aware of diseases and mutations.

‘I feel enormous guilt’** **

The mother in France who received the call back in June has since learned that her now-teenage daughter did inherit the mutation.

Months later, she and her daughter continue to grapple with what the diagnosis will mean: a lifetime of regular checks and the constant fear of what they might reveal.

She said she harbored "absolutely no ill feelings" for donor 7069, whose sperm had been sold to scores of families across the continent by the European Sperm Bank.

After all, she said, he had not known that he was a carrier of the mutation: "He is not to blame."

But, she said, "I feel enormous guilt — to know that because you chose to conceive that way, you have passed on something that is potentially life-threatening." It is, she added, "very, very hard."

*Story reported by: DR, RTBF, VRT, NOS, SVT, RUV, DW, NRK, RTVE, ORF, YLE, FTV and BBC, coordinated by the EBU Investigative Journalism Network. *

Edited by: Milan Gagnon

*Fact checking by: Julett Pineda and EBU Investigative Journalism Network *

Legal support: Florian Wagenknecht

*Do you or your child carry a genetic mutation or disease likely linked to an egg or sperm donation? Get in touch: investigations@dw.com *