Infertility isn’t something that most guys think a lot about–especially since hundreds of studies have shown that on average, being a dad is good for men. It often makes us more mature, more tolerant of others, gives us a chance to be a kid again, makes us cut back on irresponsible behavior that might land us in jail, often gets us to pay a little more attention to our health, and for some men, it gives life meaning. But what about not being a dad—whether by choice or because of a medical issue? Turns out that infertility has some extremely negative side effects for men.

For example, childless men are more likely to die of cardiovascular disease than fathers. Michael Eisenberg, a researcher at Stanford University School of Medicine, tracked 135,000 men, most of whom were in their 60s, for more than 10 years. Over the course of the study, he and his team kept track of deaths and what caused them. He very carefully eliminated men who had any kind of health issue that might have contributed to infertility, and also factored out external causes of death, such as tobacco use, alcohol abuse, accidents, and so on. After making these and a number of other adjustments, Eisenberg found that childless men were 17% more likely to die of cardiovascular disease than fathers. And the sex of the children had no effect on life expectancy.

My theory is that men with kids have healthier hearts because our kids are constantly giving them a workout by scaring the crap out of us when they wander off in the grocery store, start dating, or come home hours after curfew.

As we’ve talked about in previous articles, the majority of men want to become fathers. But not everyone is physically able to; about 15 percent of all men aged 15-45 suffer from infertility. Of those, about 600,000 have a condition called azoospermia, meaning that there are no measurable levels of sperm in their ejaculate. There are two reasons for this type of infertility: either there’s some kind of blockage which prevents healthy sperm from making their way into a man’s ejaculate, or because the testicles simply aren’t producing any sperm. Most azoospermatic men have the no-obstructive type. Several studies have found that men with infertility have an increased risk of developing testicular cancer. But Michael Eisenberg went a little further, studying both men with azoospermatic infertility and those whose infertility was due to other causes. He then compared those two groups to the general population.

Eisenberg found that the non-azoospermatic men were 1.4 times more likely than the average man to develop cancer (brain, prostate, testicular, and melanoma and lymphoma). But azoospermatic men were three times more likely to develop cancer. And men whose azoospermia was diagnosed when they were under 30 were eight times more likely to develop cancer than the general population.

The odds of developing cancer are low anyway, but whether or not you think you might ever want to have kids, you may still want to talk with your doc about getting a semen analysis, just to be sure. As Eisenberg says, “There is evidence that infertility may be a barometer for men’s overall health.”

This is part 1 of 2. In part 2, we’ll talk about several steps you can take to improve the chances that you’ll become a dad. You may also want to check out the series on sperm issues that I wrote for the Talking About Men’s Health blog. The first in the series is here.