Why are sperm donors having hundreds of children?

Some men have a huge number of children through sperm donation. this week BBC reported about a man whose sperm contained a genetic mutation that dramatically increased the risk of cancer in some of his offspring.

One of the most startling aspects of the investigation was that the man's sperm was sent to 14 countries and produced at least 197 children. The discovery provided a rare insight into the scale of the sperm donation industry.

Sperm donation allows women to become mothers when this would not otherwise be possible: if their partner is infertile, they are in a same-sex relationship or raising children alone.

Satisfying this need has become big business. The market in Europe is expected to be worth over £2 billion by 2033Moreover, Denmark is a major exporter of sperm.

So why do some sperm donors have so many children, what has made Danish or so-called “Viking sperm” so popular, and should the industry be regulated?

If you're a man reading this, we're sorry to have to tell you this, but the quality of your sperm is probably not good enough to be a donor – fewer than five in 100 volunteers actually achieve this goal.

First, you must produce enough sperm in the sample – that's your job. sperm count – then be tested to see how well they swim – their mobility – and by their form or morphology.

The sperm is also tested to ensure it can withstand freezing and storage in a sperm bank.

You can be perfectly fertile, have six children, and still not be suitable.

Rules vary around the world, but in the UK you also have to be relatively young – between 18 and 45 years old; be free from infections such as HIV and gonorrhea, and do not carry mutations that can cause genetic diseases such as cystic fibrosis, spinal muscular atrophy and sickle cell anemia.

Overall, this means that the number of people who end up donating sperm is small. In the UK, half of the sperm is imported.

But biology means that a small number of donors can produce a huge number of children. It only takes one sperm to fertilize an egg, but each ejaculation contains tens of millions of sperm.

The men will come to the clinic once or twice a week to donate blood, which can last for months.

Sarah Norcross, director of fertility and genomics charity Progress Educational Trust, said the shortage of donor sperm had made it a “precious commodity” and “sperm banks and fertility clinics are making the most of available donors to meet demand”.

Of this small pool of donors, some men's sperm is simply more popular than others.

Donors are not chosen randomly. This is similar to the harsh reality of dating apps, where some men get far more matches than others.

Depending on the sperm bank, you can look at photos, listen to their voice, find out what kind of work they do – engineer or artist? – and check their height, weight and more.

“You know, if their name is Sven, they have blond hair, they're 6ft 4ins (1.93m), they're athletic, they play the violin and speak seven languages ​​- you know that's a lot more attractive than a donor who looks like me,” says male fertility expert Professor Allan Pacey (pictured), who used to run a sperm bank in Sheffield.

“Ultimately, when it comes to donor matching, people swipe left and swipe right.”

Denmark is home to some of the world's largest sperm banks and has gained a reputation for producing “Viking babies”.

Ole Schue, the 71-year-old founder of the international sperm bank Cryos, where a single 0.5ml vial of sperm costs between €100 (£88) and more than €1,000 (£880), says the culture of sperm donation in Denmark is very different from other countries.

“The population is like one big family,” he says, “there are fewer taboos about these issues, and we are an altruistic population, with many sperm donors also donating blood.”

And this, according to Shu, allowed the country to become “one of the few exporters of sperm.”

But he argues that Danish sperm is also popular because of genetics. He told the BBC that the Danish “blue-eyed and blond-haired genes” are recessive traits, meaning they must be passed on from both parents to appear in a child.

As a result, the mother's traits, such as dark hair, “may dominate the unborn child,” Skow explains.

He says demand for donor sperm comes mainly from “single, highly educated women in their 30s who are focused on their careers and give up on family planning too late.” Now they make up 60% of requests.

One aspect sperm donor investigation Earlier this week it was revealed how the man's sperm was collected at the European Sperm Bank in Denmark and then sent to 67 fertility clinics in 14 countries.

Nations have their own rules regarding how many times the sperm of one man can be used. Sometimes it is tied to the total number of children, others are limited to a certain number of mothers (so each family can have as many related children as they wish).

The original argument around these restrictions was to prevent half-siblings who did not know they were related from meeting each other, forming relationships, and having children.

But nothing can prevent the use of sperm from the same donor in Italy and Spain, and then in the Netherlands and Belgium, provided that the rules are followed in each country.

This creates circumstances in which a sperm donor can legally father a large number of children. Although a man is often in the dark about this fact.

“Many recipients, as well as donors, are unaware that sperm from a single donor can be legally used in many different countries – a fact that needs to be better explained,” says Sarah Norcross, who argues it would be “sensible” to reduce the number of children a single donor can have.

In response to an investigation into a sperm donor who passed on a gene that led to cancer in some of his 197 children, officials in Belgium have called on the European Commission to create a pan-European registry of sperm donors to monitor the movement of sperm across borders.

Deputy Prime Minister Frank Vandenbroucke said the industry was like the “Wild West” and “the original mission of offering people the opportunity to start a family has given way to a real fertility business.”

The European Society of Human Reproduction and Embryology has also proposed limiting the number of donors to 50 families in the EU. This system would still allow one donor's sperm to produce more than 100 children if each family wanted two or more children.

Concerns have been raised about the impact on children conceived through sperm donation. Some will be happy, others may be deeply saddened by the double discovery that they were created using donor sperm and are one of hundreds of half-siblings.

The same applies to donors, who often have no idea that their sperm is being distributed so widely.

These risks are amplified by readily available DNA ancestry tests and social media where people can search for their children, siblings or donor. In the UK there is no longer anonymity for sperm donors and there is a formal procedure by which children find out the identity of their biological father.

Cryos' Mr Shue argues that further restrictions on sperm donation will simply force families “to turn to the private, completely unregulated market”.

Dr John Appleby, a medical ethicist at Lancaster University, said the implications of such widespread use of sperm presented a “huge” ethical minefield.

He said there are issues related to identity, privacy, consent, dignity and more, making it a “balancing act” between competing needs.

Dr Appleby said the infertility industry is “responsible for how many times a donor is used” but agreeing global rules would undoubtedly be “very difficult”.

He added that the proposed global sperm donor registry faces its own “ethical and legal challenges.”