Why 50 families is still too many:
Rethinking international donor limits
Currently, there is no international legislation governing sperm and egg donation.
At an international level, sperm and egg donors can donate to tens, or even hundreds, of families across the world without breaking any laws. This creates situations in which a single donor can legally have more than 100 — and sometimes over 1,000 — donor-conceived offspring. This phenomenon poses serious ethical, medical and psychological concerns for all involved, but especially for donor-conceived people.
Recently, the European Society of Human Reproduction and Embryology (ESHRE) published a paper calling for a Europe-wide limit on the number of families able to use a single donor [1] . As a first step, the paper proposes that sperm and egg donors should be used by a maximum of 50 families across Europe, with the eventual aim of reducing this number to 15 families.
As a donor-conceived person myself, I feel hesitant to fully support the proposal. While I welcome it as an important first step towards greater regulation of donor conception, I do not believe that a 50-family limit will substantially reduce the harms associated with large donor sibling networks. This is partly because the proposal applies only within Europe, and partly because 50 families remains too high to meaningfully reduce the risks associated with large donor sibling networks.
In this blog post, I will explore the legislative background of donor conception, including the development of family limits and the rise of international gamete donation and cryobanks. I will then examine some of the medical, social and psychological harms associated with large donor sibling networks.
Finally, I will outline the changes I would like to see in the international donor conception landscape and explain why, in my view, a 50-family limit remains too high.
Background
Family limits
Family limits refer to the number of families that can use a single donor’s sperm or egg to conceive. Crucially, this differs from the number of children conceived because one family can use a donor several times to conceive subsequent children. In reality, this means that one donor could donate to 50 families yet conceive over 100 children if each family has two or more children.
The introduction of family limits is a relatively recent feature of fertility law, emerging largely within the last 25–30 years. The UK was among the first countries to formalise donor family limits at a national level during the 1990s, followed by several countries across Europe.
Yet, because family limits are currently determined at the national level, there is significant variation between the limits set by each country. For example, the UK has a limit of 10 families per donor, whereas elsewhere in Europe the rules differ considerably: the Netherlands has a 12-family limit, Spain has a 6-family limit, and Germany has a 15-family limit.
Variation is even greater outside Europe. In countries such as the United States, there are still no legally enforced national limits on the number of families or children created from a single donor.
Increase in international sperm and egg donation
Over the past several decades, there has been a significant rise in demand for donor gametes, both in the UK and internationally. For instance, in the UK, births using donor eggs, sperm or embryos increased from one in 450 of all UK births in 2006 to around one in 170 in 2019 (HFEA, 2022) [2].
Due to increasing demand for donors, many countries now face shortages of gametes – both sperm and eggs – with countries becoming increasingly dependent on gametes from overseas.
In the UK, more than half (52%) of new sperm donors registered in 2020 were from donor imports, with 21% donating in Denmark, and 27% donating in the USA(HFEA, 2022) [2]. (And remember, in the US there are no legally enforced family limits!)
Despite the demand for international donors and importation of gametes, there is currently no international legislation governing these fertility practices.
The rise of prolific donors and international cryobanks
The current legislative landscape creates conditions where one donor can reach the national family limit in one country but travel across borders to continue donating. This means that without breaking any laws, a single donor can create tens or hundreds (or even thousands!) of donor conceived offspring across the world.
This has been documented in high-profile cases, such as the Netflix documentary series The Man with 1000 Kids, and reflects the emergence of so-called “super-donors” or “prolific donors”.
However, I often feel like the focus on these dramatic depictions of donor conception stories positions one individual donor as a villainous narcissist, whilst deflecting concern away from the systems that enable prolific donation.
In reality, prolific donation is not solely the result of individual donors.
International cryobanks do a similar thing.
Cryobanks – sperm and egg banks – can routinely export sperm and eggs internationally, reaching domestic family limit caps whilst exporting gametes to additional countries.
Moreover, cryobanks may underestimate the amount of children conceived from one donor. Cryobanks often rely on parents self-reporting their birth/pregnancy when monitoring numbers of donor conceived offspring, rather than the number of vials they sell. This is problematic because recent estimates suggest that only 20% to 40% of parents actually report their birth/pregnancy, meaning banks run the risk of selling a donor’s vials after their real-world family limit has been exceeded [3].
In many cases, donors themselves are unaware of how widely their gametes have been distributed. After consenting to international donation, they often lose control over where, and by whom, their donations are used.
This phenomenon of prolific donation – from both individuals and from the international fertility industry – is enabled through the lack of international regulation.
Harms associated with prolific donation
There are several harms associated with having large numbers of donor siblings, for donor conceived people and their families.
Medical harms
If a donor has a hereditary medical condition, it could be passed on to dozens – or more – of their biological children. If a donor conceived person does not know all of their half-siblings, they may miss important opportunities to share medical information and learn about genetic conditions that could require screening, monitoring or preventative treatment.
For instance, in one recent case, sperm from a donor carrying a rare cancer-causing genetic mutation was reportedly used in the conception of at least 197 children across 14 countries [4].
Social and psychological harms
For donor conceived people, discovering that they have large numbers of close genetic relatives can raise difficult questions around identity, safety and belonging. Even relatively small donor sibling networks can create emotionally complex experiences for donor conceived people. I myself have fewer than 10 donor siblings, a relatively small number by current industry standards, yet even this can feel like an overwhelmingly large number.
Another social and medical concern is consanguinity: the risk of unknowingly forming relationships with genetically-related individuals. This risk is increased when a donor conceives large numbers of donor conceived offspring.
Fertility commodification
Studies have shown that the commodification of fertility can result in donor conceived people feeling as though they were ‘mass-produced’, rather than individuals conceived through healthcare treatment [5]. This is especially prevalent given the commercial nature of cryobanks, meaning that parents can select donors through catalogues based on a donor’s physical attributes, ethnicity, professional occupation, educational attainment, skills and hobbies, with gametes priced according to demand.
To me, parental choice over the donor makes it feel less like a fertility procedure and more like a process of designing a child. This is an uncomfortable reality that some donor conceived people live with.
Conclusion
ESHRE’s proposal represents the first legislative attempt to address an increasingly international problem. For that reason alone, it deserves recognition.
However, international regulation will only be effective if it reflects the realities of the problems within the international donor conception space, as outlined in this blog.
As it stands the 50-family limit remains too unambitious to significantly reduce the risks associated with prolific donation and, despite ultimately aiming for a 15 family limit, ESHRE’s paper lacks concrete timeframes to achieve this.
Ultimately, a 50 family limit still creates conditions where individual donors can prolifically donate, and where cryobanks continue to maximise the quantity of gametes they sell. And this creates ethical concerns for all involved, but most acutely for donor conceived people.
As such, below is a list of some of the legislative changes I would like to see:
International donor registries
| The introduction of a centralised international register for medical tracing purposes and to ensure that parents are aware of how many other families have used the same donor’s sperm or eggs and to prevent the same donor from being used across multiple countries.
It is especially important for the US to participate in this register as they currently have no national family limit yet are a major gamete exporter. |
Global 15-family limit
| A global limit of 15 families per donor introduced to reduce the ethical and psychological concerns associated with very large donor sibling networks.
A reduction to 15 families may initially create greater shortages of donor gametes, particularly given the current dependence on international donors. However, I believe that the availability of donor gametes should not take priority over the wellbeing of the people conceived from them. Donor conception should not be measured solely by how many people can be helped to have children; but also by whether it provides an ethical framework that respects the long-term interests of donors, recipient parents and, crucially, donor-conceived people. A shortage of donor gametes should therefore be viewed as a challenge for the fertility industry and policymakers to address through better donor recruitment, retention and regulation and not as a justification for creating larger donor sibling networks. |
Donor sibling registry
| A centralised global donor sibling registry in which donor conceived people can voluntarily opt in at the age of 18 in order to connect with donor siblings. |
Mandatory medical updates
| If a donor or donor conceived child develops a serious inherited medical condition, there should be a mandatory obligation to update the register so that medical information can be shared with other donor- conceived siblings. |
Increased donor autonomy
| All cryobanks should allow donors to set a lower limit for the number of families that can be created with their own gametes. |
Links
[1]- ESHRE Paper 2025 https://www.eshre.eu/Europe/Position-statements/Stakeholder-review
[2]- Embryos increased from 1 in 450 of all UK births in 2006 to around 1 in 170 in 2019 (HFEA, 2022) https://www.hfea.gov.uk/about-us/publications/research-and-data/trends-in-egg-sperm-and-embryo-donation-2020/
[3]- 20% to 40% of parents actually report their pregnancy, meaning cryobanks continue selling a donor’s vials after their real-world family limit has been exceeded https://www.lgbtqnation.com/2025/02/what-the-sperm-banks-wont-tell-you-inside-the-shocking-world-of-donor-conception/
[4]- Sperm from a donor carrying a rare cancer-causing genetic mutation was reportedly used in the conception of at least 197 children across 14 countries
https://www.bbc.co.uk/news/articles/ckgmy90z991o
[5]- Studies have shown that the commodification of fertility can result in donor-conceived people feeling as though they were ‘mass-produced’, rather than individuals conceived through healthcare treatment
Written by Sarah
DCP Voices
August 2026
