How many children can one donor have?
In the United States, there is a recommendation, no limit, and no registry.
Prospective parents often assume there is a cap. In the United States there is not one.
What exists is a professional recommendation. The fertility societies' donation guidance states that limiting a single donor to no more than 25 births would avoid any significant increased risk of inadvertent consanguineous conception
in a population of 800,000, and immediately adds that this may require modification when the population using DI represents an isolated subgroup or when the specimens are distributed over a wide geographic area.
Three structural facts follow, and all three should be said plainly:
- The 25-per-800,000 figure is a recommendation, not a regulation. Nothing in the federal tissue rules limits offspring number.
- Compliance depends on recipients voluntarily reporting births back to the bank, and many never do. So the count for any donor is systematically an undercount, and the true number is unknowable.
- There is no US national donor registry. The largest tracking mechanism is a privately run voluntary matching service, which is not a census.
What is documented, in a court ruling rather than a medical journal, is a Dutch case: in April 2023 the District Court of The Hague ordered a donor to stop donating after finding he had fathered at least 550 children internationally. That is not US data and it is not a clinical finding. It is evidence that the absence of enforceable limits is not a hypothetical concern.
If the number of half-siblings your child may have matters to you, and for many families it does, ask the bank directly: how many reported births does this donor have, how do you count them, and what is your own limit? All three answers are worth having in writing.