Sperm Donor Limit: Spain 6, UK 10, a Danish Bank 75 Worldwide

Most European countries cap how many families one sperm donor can help. Spain allows six children, the UK ten families, Denmark and the Netherlands twelve.¹ Each of those limits stops at the border.

Europe's largest sperm banks sell abroad, and their own caps are much higher. The European Sperm Bank in Denmark sets a limit of 75 families worldwide for most of its donors.² In July 2026 the European Society of Human Reproduction and Embryology (ESHRE) proposed an EU-wide limit instead: 50 families per donor, falling over time to 15 or fewer.¹

The national limits, and what each one counts

Sources: ESHRE position paper, Appendix 1,¹ Spain's assisted reproduction law,³ European Sperm Bank.²

The limits do not count the same thing. Spain counts children, and its law says so precisely: no more than six "children born in Spain" from one donor's gametes.³ ESHRE's table notes that Spain's six includes the donor's own children.¹ The UK, Denmark and the Netherlands count families, so siblings from the same donor do not use up extra places.¹

Germany's 15 is a recommendation, not a law.¹ Cyprus and Malta allow a single child per donor.¹

Why the limits stop at the border

Spain's law shows the problem in its own wording. It limits children "born in Spain".³ A Spanish donor's sperm used in another country does not count toward the six.

The UK regulator says the same about its own rule. The Human Fertilisation and Embryology Authority (HFEA) tells clinics to limit a donor to 10 families in the UK. Because rules differ abroad, it says, a donor's sperm "could be used to create additional families before or after the importation to the UK."⁴

That matters because the UK relies on imports. In 2020, 52% of newly registered sperm donors in the UK came from imports, up from 22% in 2010.⁴ The main sources were the US, at 27% of new donors, and Denmark, at 21%.⁴ MIT Technology Review reported the same picture independently: more than half of UK donations in 2020 were imported, mostly from Denmark or the US.⁵

Belgium is more exposed still. ESHRE cites a 2014 study which found that 63% of inseminations with donor sperm in Belgium used sperm imported from Denmark.¹

What happened when the limits failed

One case ESHRE cites involved a donor to the European Sperm Bank. He carried a rare mutation in TP53, a gene linked to cancer. His sperm was used to conceive at least 197 children across Europe, according to an investigation by 14 broadcasters reported by STAT.⁶

In Belgium, where a donor is meant to reach six families, 38 women had 53 children with his sperm.⁶ ESHRE says the Danish bank supplied that donor's sperm to at least 14 Belgian clinics.¹

ESHRE's paper explains why no one stopped it. The authority that regulates the Danish bank "does not have a mandate to enforce the national regulations of the receiving country."¹ The bank told STAT the limits had "unfortunately" been exceeded in some countries.⁶

A second case predates it. A Dutch court ordered one donor to stop in 2023, after it emerged that at least 550 people had been conceived with his sperm through clinics, banks and private donations.¹

What ESHRE now proposes

ESHRE published its position paper in July 2026. Its main recommendations:¹

• A starting limit of 50 families per donor across the EU, reduced in stages to 15 families or fewer.
• National limits stay in force where they are lower. The EU cap would sit on top of them, not replace them.
• A 20-year cut-off. A donor's sperm should not go to new families more than 20 years after the first donation.
• An EU-wide donor registry, covering imports from outside the EU as well.
• Banks outside the EU must meet the limit before they can export into it.

ESHRE calls 50 families "a major reduction" on current practice. Some banks set their own limits as high as 75 families, it notes, and some set none.¹

What the limits leave out

A lower limit has costs. ESHRE itself warns that tighter caps mean fewer families per donor. Unless banks recruit more donors, patients could wait longer and pay more, and some may turn to unregulated private donors.¹

National registries cannot see across borders. The Netherlands built a register in 2025 that gives each donor 12 codes, one per family.⁷ DutchNews reported that it will not stop a donor registering in another country.⁷

Nobody knows the right number. ESHRE says its 15-family target should be revised as research comes in.¹ A 2020 survey of 233 sperm donors in Denmark and the US found 48.5% comfortable with more than 100 offspring, or saying the number did not matter.¹

The proposal is not law. As of October 2026 it is a position paper from a professional society. A binding EU limit would need new legislation, which ESHRE suggests could come under the EU's rules on substances of human origin.¹

How to use this if you are buying donor sperm abroad

Ask the bank for the donor's worldwide family limit, not the national one. The European Sperm Bank publishes its 75-family cap and a 25-family option in selected markets.² Some US banks limit donors to about 25 families, according to MIT Technology Review.⁵

Then ask how the bank counts families and how quickly pregnancies are reported. The European Sperm Bank says a donor can occasionally exceed its limit when a pregnancy is reported late.² A lower cap is only as good as the reporting behind it.

Footnotes

1. https://www.eshre.eu/-/media/sitecore-files/Advocacy/ESHRE_PositionPaper_Limits-2506.pdf — European Society of Human Reproduction and Embryology, "ESHRE position paper: international limits on the number of offspring per gamete donor", including Appendix 1, national donor offspring limits (published Jul 2026). Accessed Oct 23, 2026. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷

2. https://www.europeanspermbank.com/en/getting-started/family-limits — European Sperm Bank, "Our family limits". Accessed Oct 23, 2026. ↩ ↩² ↩³ ↩⁴

3. https://www.boe.es/buscar/act.php?id=BOE-A-2006-9292 — Boletín Oficial del Estado, Ley 14/2006, de 26 de mayo, sobre técnicas de reproducción humana asistida, article 5.7 (consolidated text). Accessed Oct 23, 2026. ↩ ↩² ↩³

4. https://www.hfea.gov.uk/about-us/publications/research-and-data/trends-in-egg-sperm-and-embryo-donation-2020/ — Human Fertilisation and Embryology Authority, "Trends in egg, sperm and embryo donation 2020" (published Nov 2022). Accessed Oct 23, 2026. ↩ ↩² ↩³

5. https://www.technologyreview.com/2026/07/10/1140289/sperm-donors-need-limits-says-a-european-fertility-group/ — MIT Technology Review, Jessica Hamzelou, report on the ESHRE donor-limit position paper (published Jul 10, 2026). Accessed Oct 23, 2026. ↩ ↩²

6. https://www.statnews.com/2025/12/10/200-children-inherit-gene-mutation-one-sperm-donor/ — STAT, reporting an investigation by 14 European broadcasters in the European Broadcasting Union's Investigative Journalism Network (published Dec 10, 2025). Accessed Oct 23, 2026. ↩ ↩² ↩³

7. https://dutchnews.nl/2025/04/new-sperm-donation-rules-to-enforce-12-family-limit-for-donors — DutchNews, "New sperm donation rules to enforce 12-family limit for donors" (published Apr 1, 2025). Accessed Oct 23, 2026. ↩ ↩²

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