Jan. 18, 2023 – Only about 4% of men who signed up to be sperm donors in the United States or Denmark completed the process and had their sperm frozen for use in medically assisted reproduction, new research reveals.
Some men apply online, have their sperm tested, but do not go any further in the process. Others are rejected because of low thawed sperm quality, a self-reported health condition, or from failure to pass an infectious disease test or genetic screening.
These low figures should not discourage men who wish to become sperm donors, says Allan Pacey, PhD, lead author of the study and professor of andrology at the University of Sheffield in the U.K.
“A constant supply of new donor applicants is needed. So my advice to would-be donors is don’t be put off by the low success rates,” he says. “We need men to come forward to be screened and see if sperm donation is for them.”
The findings were published online this month in the journal Human Reproduction.
Most previous studies focused on the safety or feasibility of using frozen sperm samples. Only a few examine the success rate for men who apply to become sperm donors.
The 4% figure was not unexpected for Pacey.
“When I ran a small sperm bank in Sheffield, we would also only accept less than 4 in 100 applicants. This shows how hard it is to pass the screening tests to become a donor,” he says.
But the 4 in 100 completion rate surprised Michael Thomas, MD, president of the American Society for Reproductive Medicine.
“Four out of one hundred is much lower than I would have expected,” he says, noting that he he tells potential sperm donors the acceptance rate is between 20% and 30%.
A Rare Look Into the Business
The study is worthwhile for its insight into the sperm bank business, Thomas says.
“The business associated with sperm donation has [not] been studied in this detail recently. It’s nice to know more about how the industry works,” he says.
One cautious note is that the researchers evaluated one sperm bank, Cryos International, while there are many others in the U.S. and abroad, says Thomas, who also is professor and chair of obstetrics and gynecology at the University of Cincinnati College of Medicine in Ohio.
“It is unclear if these study results are the same for every company,” he says.
“These guys were obviously very selective,” Thomas says. “The fact that the only 4% made it that tells you that they’re not just taking any person that walks in the door.”
“It’s not the days anymore where you get college kids to come in because they want to make fifty dollars of beer money.”
Anonymous No More?
It’s also no longer a time where a majority of sperm donors are guaranteed anonymity. The popularity of commercial genetic companies like ancestry.com and 23andMe are driving this change, Thomas says.
“Now people are starting to find each other as far as either siblings of the same sperm donor, or other kids who were born from sperm donation. And they are asking some very tough questions — especially when it comes to their own personal genetics.”
As a result, “these folks who’ve never thought they would be found are starting to be found.”
Adults who were conceived by donor are also calling for more transparency regarding their genetic connections, he notes.
The U.K. researchers focused on the U.S. and Denmark for a couple of reasons. One 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.
Also, the U.K. relies on sperm donations from the U.S. and Denmark. One government agency reports that more than half of new donor registrations in the U.K. involved international donors in 2020, for example.
Another finding is that sperm donors who shared their identity were more likely to complete the process, 4.7%, compared to 3.2% of anonymous donors,
“What’s particularly fascinating is that more donors, who initially wanted to remain anonymous, were willing to be identifiable as the screening and donation process continued,” Pacey says in the release. “This is particularly good news for patients in the UK undergoing fertility treatment, as it is a legal requirement for sperm donors to be identifiable to any children born from their donations.”
Donors in Denmark were also more likely to be ultimately approved, 6%, compared to only 1% of Americans.
Another take away message, Thomas says, is “that the number of sperm donors has decreased, which disadvantages same-sex couples, single women, or heterosexual couples with a male factor or genetic issue.”
Not discussed “is that the number of sperm donors who are of color are probably much lower than the 4 in 100,” he notes.
Going forward, Pacey wishes to continue the research.
“We will hopefully be drilling into much more detail about why so many men are put off from the process and why there are differences between men in Denmark and the USA,” he says. “If we could streamline the donor recruitment processes in those two parts of the world and make them more country-specific, then we might be able to recruit a few more donors.”