The maternity department at Puerto Vallarta’s hospital had better brace itself. There’s evidence that a sudden drop in air pressure can induce early labor, and Hurricane Patricia is clocking in the lowest pressures ever seen.

The superstorm is coming in hot towards Mexico’s west coast, and showing no signs of slowing. The estimated pressure in the eye of the storm has dipped to 880 millibars, a record for that part of the world.

That’s 13 percent lower than normal atmospheric pressure, which is 1,013 millibars. So imagine a void of air that significant, and the weight of the entire hurricane rushing in to fill it.

The storm’s so big, the eye can be easily seen from the International Space Station:

So what does this have to do with babies? There’s a common myth that hurricanes bring on labor, because the drop in pressure makes it more likely that a pregnant woman’s water will break.

And, as it turns out, there’s some science to support the theory. This Japanese study found a correlation between low barometric pressure and women going into labor. They also saw more water break after change in atmospheric pressure, whether it went down or up.

But other studies have failed to find a conclusive link. One team of obstetricians tried to find evidence that Hurricane Andrew caused an outburst of births in Miami in 1992, but they were unable to, according to LiveScience.

It may be that, like a lot of old wives’ tales, the myth has persisted for so long because there’s something to it, although science has so far not been able to come up with a good explanation for how and why.

Regardless, if I were close to my due date and in Puerto Vallarta today, I’d be thinking about the quickest way to a safe birthing place right about now.

Photos via NOAA