The concept of a sperm count is not something guys think about much.

In fact, unless you’re actively trying to conceive with a partner, there’s a good chance you don’t think about it at all. Which isn’t unreasonable — a lot of the time, if guys are spending any time worrying about what they’re ejaculating, they’re more concerned with the size of their loads than how many sperm are in them.

But that could be changing. Recent, reliable data suggests that sperm count numbers are dropping around the world and have been for several decades now.

In order to get a better sense of what’s going on in the world of sperm counts, how it affects our readers and what you can do about it, AskMen spoke to a couple of fertility experts. Here’s what they had to say:

Now, as you may be well aware, it only takes one sperm to fertilize an egg. You don’t need millions upon millions of sperm in order to conceive, and even if sperm counts are down, they’re still, on average, in the tens of millions per milliliter of ejaculate.

But scientists suggest a high sperm count is a sort of fail-safe measure against being unable to reproduce, as even a best-case scenario in terms of sperm count and ovulation may only produce a 10% chance of creating a pregnancy. The lower your sperm count, the more times it may take to be able to conceive.

“The authors of this research stated that sperm counts have dropped so low that it can make conception difficult,” says men’s sexual health and wellness expert Brenden Durell, “and the average couple around the world would need to seek medical treatment in order to conceive.”

These findings strongly suggest a dramatic decrease in male reproductive health, which has serious, broader implications beyond fertility.”

Loy also points out that, while the worldwide trend is downward, “there were no significant declines in sperm counts in studies from South America, Asia, and Africa.” However, he notes, this may be due in part to “an absence of such studies from these countries prior to 1985.”

It would be helpful if there was an easy thing we could point to and identify as the culprit, but, as is often the case with public health concerns, there’s no one clear factor to blame here — at least, not yet.

“It’s difficult to pinpoint any specific causes as to why sperm counts are dropping,” says Dr. Robles. “It is likely due to a combination of factors, including environmental and lifestyle factors such as poor diet and exposure to endocrine-disrupting chemicals.”

“Studies done by scientists at the University of Aberdeen and Hasselt University found evidence of ‘forever chemicals’ impacting the body from early stages of infancy, which can potentially impact fertility later in life,” says Durell, who also noted that air pollution has been linked to infertility by other studies.

Diet can also be a factor — but a potentially tricky one. While eating a diet rich in fruits and vegetables would correlate with better overall health, often a significant factor in sperm health, organic produce seems like it’s the way to go. That’s because pesticides may be a significant factor in lowered sperm counts, according to a 2015 study Durell mentioned.

Another surprising possible factor? How tight your underwear is — specifically, whether they are hugging your testicles to your pelvis.

So what does this mean for you? If you’re not actively trying to conceive, maybe not much.

There’s also a broader context to consider. After all, no one goes through a public health crisis alone.

“This is a humanity-based topic that needs to be dealt with one man at a time,” he adds. “As a men’s intimacy and emotional health coach, I see this impacting every man, whether his individual sperm counts are low or not.”

“If it’s not you, it may be impacting your best friend, your brother, your co-worker,” Durell points out. “In indigenous cultures, not being able to conceive has a profound impact on the social well-being of the couple and community negatively, according to this case study done in a village in Ghana. It’s highly stigmatized.”

Though infertility isn’t much discussed in the West, Durell notes that infertility is somewhat similarly stigmatized here too.

“Declining sperm counts may be an indicator of a man’s overall hormonal health,” says Dr. Robles. actively trying to conceive, or are preparing to, it’s a bit of a different story, as the downward trend in global sperm counts may be affecting you personally in very real ways in the present or immediate future.

“Low sperm counts may negatively impact the chances of conceiving a child naturally,” Dr. Robles notes. “This is the primary reason why we always check a semen analysis in couples who are having difficulty achieving pregnancy.”

“Because of this,” Loy says, “if a couple is having trouble conceiving, it’s just as important for the male partner to undergo diagnostic testing to determine the cause of infertility. The data around global sperm count and concentration furthers the need for a fertility evaluation to include male partners.”

“A fertility evaluation will give men a clear understanding of their fertility health,” says Dr. Loy. “These are typically done through noninvasive testing,” he notes, including methods like blood tests, urine tests, or even transrectal ultrasounds.

Once you get your results, Durell notes, you’ll be able to understand what your sperm count level is like, which will give you “a better understanding of the action to take.”

“I encourage men who may have a lower sperm count to adopt the mindset that they aren’t broken or lacking,” he says. “It’s an invitation to be more proactive with learning new activities, new foods, supplements and an overall new lifestyle.”

If you’re in this position, Dr. Loy recommends trying to live “as healthy a lifestyle as possible.”

Those chemicals and other substances to avoid?