European Fertility Group Pushes for a Continent-Wide Cap on Sperm Donations

A European fertility organization is calling for a coordinated limit on how many families a single sperm or egg donor can contribute to, arguing that national rules have failed to keep pace with cross-border sperm trade and consumer DNA testing.

At a European Society of Human Reproduction and Embryology (ESHRE) meeting in London on July 8, researchers laid out a plan asking sperm and egg banks and fertility clinics to respect an initial ceiling of 50 families per donor across Europe, according to MIT Technology Review. The group frames that number as a starting point rather than a target, and wants the region to move toward a stricter cap of 15 families per donor.

"The only thing that really makes sense is a transnational limit," said Jackson Kirkman-Brown, a professor of reproductive biology at the University of Birmingham, at the meeting. Kirkman-Brown and colleagues spent months assembling ESHRE's position after consulting fertility specialists, clinics, sperm and egg banks, donors, and donor-conceived people.

Why national limits are breaking down

Many countries already cap donations. Malta and Cyprus permit a single egg or sperm donor to contribute to just one birth, according to data presented at the ESHRE meeting. The UK sets its limit at 10 families per donor, and Denmark at 12.

The problem is enforcement. Donated gametes do not stay within their country of origin. Denmark is a major sperm exporter, and in the UK more than half of sperm donations in 2020 were imported, with most coming from Denmark or the United States. A limit that stops at a national border does little when the same donor's sperm is shipped to clinics in several countries.

Genetic testing has made the gaps visible. Services from companies such as Ancestry and 23andMe, combined with genetic registries, now let donor-conceived people trace biological parents and siblings even in places where donor anonymity was legally guaranteed. Because sperm can be frozen for years, some people learn the identity of a genetic parent only after that person has died, or discover siblings of widely different ages scattered across the world.

The cases driving the debate

The scale can be extreme. Sperm from Jonathan Meijer, a Dutch donor who began in 2007, was used to conceive between 550 and 600 children. Stichting Donorkind, a foundation and advocacy group for donor-conceived people, took him to court, and he was ordered to stop donating in 2023.

There is also a health argument. A donor at a Danish sperm bank was later found to carry a genetic mutation that significantly raised the risk of multiple cancers. By then his sperm had been used to conceive at least 197 children across Europe. Some of those children developed cancer, and some died. Screening makes such outcomes unlikely, but the case shows what happens when a single donor's genetic material spreads widely before a problem surfaces.

Beyond disease, a large sibling network raises the risk that donor-conceived people could unknowingly form romantic relationships with genetic relatives. And the sheer numbers can be difficult for the people involved. One woman who found 25 half-siblings over seven years told the Guardian the experience made her feel "a bit mass-produced."

Disagreement on the right number

Even supporters of the proposal say 50 families is high. "We may find that 15 is also too high," said Vasanti Jadva, who studies the psychological well-being of donor-conceived people at City St George's in London. "We still don't know what the right number is."

Ties van der Meer, the 47-year-old who chairs Stichting Donorkind and was himself donor-conceived, argues that even five families per donor would be too many, and that international contributions should be capped at two families to make it easier for donor-conceived people to connect with genetic relatives. He still called ESHRE's proposal a "positive first step."

US practice sits in a different place. When asked about the ESHRE proposal, the American Society of Reproductive Medicine pointed to a guidance document suggesting that for a population of 800,000, a single donor should account for no more than 25 births to reduce the chance of relatives having children together. Many US sperm banks cap donors at around 25 families.

The enforcement question

Setting a number is easier than making it stick. ESHRE's own advocates acknowledge that European limits will be hard to enforce, and international limits harder still. There is also a supply risk: if regulated donations become scarcer, some prospective parents may turn to unregulated donors who skip health screening. That route carries its own hazards, including the possibility that a donor later seeks parental rights over children conceived with his sperm.

For now the proposal is a position, not a law. But its backers argue that the combination of frozen gametes, cross-border shipping, and cheap DNA testing has already outrun the country-by-country system. As van der Meer put it, "you have to start somewhere."