It’s that time of year when major snowstorms leave millions of Americans stocking up on bread and toilet paper, hunkering down in their homes… and having sex. Yup, the common cultural belief that big weather events like blizzards and hurricanes contribute to lots and lots of babies 40 weeks later is strong. But before you wink wink nudge nudge your couple friends about their winter storm plans, is it actually true that blizzards = baby booms?

While it might be fun (and funny!) to imagine legions of babies being conceived during blizzards, Mark Mather, associate vice president at the US-based Population Reference Bureau, says that weather events don’t actually result in higher birth rates after 9 months: “This idea comes up every now and then, but there is not a lot of hard evidence linking blizzards or other weather-related events to fertility rates. There was one study that linked tropical storms to a slight increase in births in the South. But most of the other evidence has been anecdotal.”

The study Mather is referring to, published in 2008 in the Journal of Population Economics, did find higher birth rates associated with low-level hurricane advisories. It also found lower fertility associated with more severe hurricane advisories. So, the higher the risk of the storm, the less chance people were actually spending their time having sex. There may be slightly more babies born if people are just bored and cooped up like they might be during a big snowstorm, but if they feel their lives are actually at risk, there’s no time to spend in bed.

Still, Mather emphasizes that we shouldn’t take the study as too illustrative, saying, “The problem is that fertility is determined by a wide range of social, economic, and demographic factors. So even if you find a correlation between weather events and births, it’s hard to know if this is a causal relationship because there are so many other explanatory factors that could be involved.”

And of course, there’s only a few days a during menstrual cycle that a woman can actually get pregnant — about 6 days around the release of an egg, in fact. The egg itself lives for about 24 hours after ovulation, but sperm can live up for five days inside of the female reproductive tract. So, if sex has happened soon enough before (or during!) ovulation, pregnancy IS possible. Still, that’s a lot of biological factors that have to fall into place alongside those snowflakes, you know?

That doesn’t mean you shouldn’t engage in conceiving your own blizzard baby if you find yourself snowed in — just know that he or she probably won’t be part of a big regional baby boom.

Carrie Murphy is a freelance writer and doula in Albuquerque, NM. Read more on her website, carrie-murphy.com.