A young couple sit inside their blue, two-story suburban home. An American flag flaps on the porch, framing the view of a nearby meetinghouse steeple and the unassuming sprawl of Eagle Mountain, Utah. A light coat of snow blankets their lawn. Children laugh on a playground that sounds close and far away at once. It’s tranquil. It’s normal.
Mitch and Ellyn Daley met on a dating app in 2016, while living in Arizona. They got married in May 2018 and began trying to start a family the following January. They figured by the beginning of 2020, they’d be parents. But after several months, they weren’t able to get pregnant. That fall, Ellyn visited her gynecologist’s office for a series of tests that turned up nothing. Just keep trying, her doctor told her, and come back soon.
Approaching her 35th birthday, she worried her biological clock had counted down — but the tests with fertility specialists kept coming back normal. This led doctors to take a closer look at Mitch. The first test was a semen analysis. They ran it twice just to be sure they finally had their answer: Mitch’s sperm count was zero.
A growing body of research suggests a similar pattern is afflicting men across the world. Published late last year in the journal Human Reproduction Update, a review by a team of researchers in five countries found that over the past 50 years, sperm counts have plummeted on every continent by about 50 percent. Another data set found that the problem is accelerating, leading to the startling conclusion that by 2045, the average man around the world will need fertility assistance to conceive a child. Some in the field of fertility question the results and implications, but on this much everyone seems to agree: The findings are striking enough to merit more study and more questions in the years ahead.
The Human Reproduction Update review was a follow-up to a similarly groundbreaking study published by the same group in 2017. The main difference was that while the first study found evidence of declining sperm counts in North America, Europe and Oceania, the new study found similar decreases in Africa, Asia and Central and South America. The resulting headlines published by various outlets boded an existential threat of the highest order. But Shanna Swan, a professor of environmental medicine and public health at the Icahn School of Medicine in New York City and a co-author of the study, doesn’t like to throw around vague terms like “existential.” After spending decades studying the intersection of sperm, fertility and chemicals, though, she believes it’s a critical issue. “It points to a serious threat to populations,” she says.
By 2045, the average man around the world will need fertility assistance to conceive a child.
Given such stark possibilities, the 2017 study has been heavily scrutinized on multiple fronts. A group from Columbia University, University of Massachusetts-Boston, Harvard and MIT criticized the assumption many observers make in equating sperm count with fertility, when no such thing as an “optimal” sperm count exists.
Dr. Paul Turek, whose Los Angeles clinic ranks among the foremost in the world for treating male infertility, seconds that observation, preferring “fecundity” — the biological capacity to reproduce — as a better measure of humanity’s reproductive health. Turek was part of a group supported by the National Institutes of Health to assess whether human fecundity was actually changing. In concluding their studies, the team could not confirm that there had been any change, but they also couldn’t rule it out.
In any case, Turek echoes the idea that falling sperm counts don’t necessarily mean doom. “If it’s true, which should certainly be entertained, it may be the case that we are simply more fertile than ever and that less sperm is needed to accomplish the same level of fertility,” he says. “Whether this theory of falling sperm counts is a ‘fact’ will be determined by time, validating studies or information, and proof from other sources.”
To raise an even simpler problem: It’s just plain hard to count sperm. “Semen is a viscous fluid,” explains Allan Pacey, a professor of andrology at the United Kingdom’s University of Sheffield, “and so it is very hard to be sure that the sample removed for testing is truly representative.” That’s especially true, Pacey contends, when you’re talking about a study that looks at 50 years’ worth of collected data. Like the Harvard/MIT group, Pacey commends the international group of researchers for their rigorous methodology. However, “My long-standing concern is whether the underlying data that they used is accurate,” he says. “It was never collected for use in this purpose, and we have improved our measurements of sperm concentration dramatically in recent years.”
Swan insists that her group’s study accounted for that by including data only from studies that used the same method to count sperm, meaning the measurements should be standardized. “If they used the methods they said they used, then every study used the same method of counting,” she says. “So that is a nonissue.” In addition, she agrees with the idea that there’s much more to reproductive health than sperm count. “Sperm counts are just, if you will, the tip of the iceberg,” she says. “They’re one marker of reproductive function.”
Researchers can also consider sperm size or motility or shape; they can factor in female reproductive changes; and when considering all of these different branches of inquiry, they can start piecing together answers about the overall reproductive health of the human species. Sperm counts are just one part of that puzzle; on this, Swan and Turek agree. Their take on the significance of these studies is less compatible. “It’s been extremely well accepted,” Swan says. “Undoubtedly a few critics here and there, but nothing that’s really challenged our findings.”
Certain chemicals — present in everything from shampoo to paint — are wreaking havoc on men’s reproductive health in concert with lincreased stress, alcohol consumption and obesity.
Those findings continue to tell a story: Sperm counts seem to be dropping around the world. But we still don’t know why. Swan has been pondering that question since the mid-1990s when she served on a committee assembled by the National Academy of Sciences to explore the impact of “endocrine-disrupting chemicals” on human health. Over many years of research, including a 2006 study that established a strong correlation between pesticide use in rural America and diminished sperm quality, she came to believe that certain chemicals — present in everything from shampoo to paint — are wreaking havoc on men’s reproductive health in concert with lifestyle issues like increased stress, alcohol consumption and obesity.
These findings culminated in her 2021 book, provocatively titled “Count Down: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperiling the Future of the Human Race.” In terms of solutions, “the advice that the doctor will give in terms of lifestyle will be helpful for reproductive health as well,” she says. “But beyond that, I think we need more people asking for better regulation. And good luck on that.”
In any case, that does little for folks who are already having issues. Mitch and Ellyn, for instance, tried multiple avenues to finally fulfill their goal of becoming parents. First, they explored traditional male fertility treatments with a specialist at the University of Utah. But those treatments would have cost them thousands of dollars with very low chances of success.
Next, they tried adoption. Going through a formal agency, it turned out, was even more expensive, so they opted for private adoption. They kept in touch with the prospective mother of their child throughout her pregnancy — right up until she decided, a few days before giving birth, that she didn’t want to give the baby up for adoption anymore.
The Daleys enrolled in classes to become foster parents. After achieving the necessary certifications, they waited a year and a half until finally, the state placed a two-month-old in their care. They had the child for three months until a court decision to send her to live with a grandparent. “That was really heartbreaking to give that baby back,” Mitch says. “So that kind of turned us off to foster care.”
They considered sperm donation, but something about the idea of a baby with only half of their DNA didn’t feel right. In February 2021, Ellyn’s mom offered an alternative: Embryo adoption. Basically, couples who conceive through in vitro fertilization sometimes produce more embryos than they need. Those fertilized eggs can be stored and, eventually, implanted — whether in the couple who created them, or not. The process resulted in the couple’s daughter, Abigail, who was born in July. They plan to pursue the same procedure once again later this year.
This is exactly the sort of thing Swan expects will become more common in coming years. “People are going to depend more and more on assisted reproductive technologies,” she says. “And I think that’s fine.”
She’s happy to see people talking more openly about it like Mitch and Ellyn have. Just recently, Ellyn had a conversation with a neighbor in their quiet slice of suburbia that quickly entered familiar territory. “She said her husband had very similar problems,” Ellyn says. “And I’ve had friends that don’t necessarily have exactly what he has, but they have low sperm counts.”
That sort of networking can help destigmatize the issue as it becomes more common. But it also speaks to one of the biggest dangers a plummeting global sperm count presents to human reproductive health. “This is not equally available,” Swan says. “Your economic status and your social status affect how you can respond to these threats. And so I think it’s an environmental justice issue as well as a reproductive environmental issue, and I’m very concerned for all those reasons.”
Back in Eagle Mountain, a closer look at the snow outside the blue house reveals big and little footprints, side by side — evidence for all to see of the growing Daley family. The scars they endured to get there, however, remain mostly invisible. As they do for many. At least for now. “For most men that’s not something they want to bring up. They feel like it’s an embarrassment. But for me, that’s life,” Mitch says, with Abigail cooing at him from Ellyn’s lap. “I can’t change it.”