January 18, 2023 – New research shows that only about 4% of men who've come forward as sperm donors within the United States or Denmark have accomplished the method and had their sperm frozen to be used in medically assisted reproduction.
Some men apply online, have their sperm tested, but don't progress. Others are rejected because the standard of the thawed sperm is poor, they self-report a health condition, or they fail an infection test or genetic screening.
These low numbers shouldn't discourage men who wish to develop into sperm donors, says Dr. Allan Pacey, lead creator of the study and professor of andrology on the University of Sheffield within the UK.
“There needs to be a constant flow of new donor applicants, so my advice to potential donors is not to be put off by the low success rates,” he says. “We need men to get screened and see if sperm donation is an option for them.”
The results were published online this month within the Journal Human reproduction.
Most studies to this point have focused on the security or feasibility of using frozen sperm samples. Few examine the success rate amongst men applying to be sperm donors.
The 4% figure was not unexpected for Pacey.
“When I ran a small sperm bank in Sheffield, we also accepted fewer than four out of 100 applicants. This shows how difficult it is to pass the screening tests to become a donor,” he says.
But the completion rate of 4 out of 100 surprised Dr. Michael Thomas, president of the American Society for Reproductive Medicine.
“Four out of a hundred is much less than I would have expected,” he says, mentioning that he tells potential sperm donors that the acceptance rate is between 20 and 30 percent.
A rare insight into the business
The study is worth it due to insights it provides into the sperm banking business, says Thomas.
“The sperm donation business is [not] has been studied in such detail recently. It's nice to know more about how the industry works,” he says.
One caveat is that the researchers studied only one sperm bank, Cryos International, while there are many others in the U.S. and abroad, says Thomas, who is also a professor and chair of obstetrics and gynecology at the University of Cincinnati College of Medicine in Ohio.
“It is unclear whether these study results are the same for all companies,” he says.
“These people were obviously very selective,” says Thomas. “The proven fact that only 4% made it shows that they're not only taking anyone who walks within the door.”
“The days of attracting college kids because they desired to make $50 on beer are over.”
No longer anonymous?
It's also no longer the case that most sperm donors are guaranteed anonymity. The popularity of commercial genetic engineering companies like ancestry.com and 23andMe is driving this change, says Thomas.
“Now persons are starting to seek out one another, either through siblings of the identical sperm donor or through other children born through sperm donation. And they're asking some very difficult questions – especially in relation to their very own personal genetics.”
The result is that “these people who never thought they would be found, are now found.”
Adults conceived through sperm donation have also called for more transparency regarding their genetic connections, he notes.
International insights
The British researchers focused on the United States and Denmark for several reasons. One of them is that they were able to study all men who applied to Cryos International in 2018 and 2019. The study included 11,702 potential donors in the two countries.
In addition, the UK is dependent on sperm donations from the USA and Denmark. A government agency reports that more than the half of new donor registrations in the UK in 2020, for example, were international donors.
Another finding is that sperm donors who revealed their identity were 4.7% more likely to complete the process, compared to 3.2% of anonymous donors.
“What is especially fascinating is that because the screening and donation process progressed, increasingly donors who initially desired to remain anonymous were willing to reveal their identities,” Pacey said in the press release. “This is especially excellent news for patients within the UK undergoing fertility treatment, because it is a legal requirement that sperm donors should be identifiable for any children born from their donations.”
The probability of final approval was also higher among Danish donors (6%) than 1% in the USA.
Another message to take away, says Thomas, is that “the variety of sperm donors has declined, which puts same-sex couples, single women or heterosexual couples with a male factor or a genetic problem at an obstacle.”
What is not discussed is that “the number of black sperm donors is probably much lower than 4 out of 100,” he notes.
Future directions
Pacey would like to continue the research in the future.
“We will hopefully discover in rather more detail why so many men are postpone by the method and why there are differences between men in Denmark and the US,” he says. “If we could streamline the donor recruitment processes in those two parts of the world and make them more country-specific, we would find a way to draw just a few more donors.”