Is Smoking Pot Before Pregnancy Risky Business?

If you've ever smoked pot, a new study from Australia that links pre-pregnancy marijuana use with preterm birth is probably enough to make you paranoid. But are these latest statistics true—or just a fluke? We asked some experts to clear the air.

The study itself looked at more than 3,000 pregnant women in Australia and New Zealand in order to detail common risk factors for preterm birth. Some of the factors, such as a family history for low birth weight babies, preeclampsia, and having Type 1 or Type 2 diabetes, doesn't come as much of a surprise. But this one does: moms who reported ever using marijuana prior to becoming pregnant had more than double the risk for premature birth. Going by this study, women who smoke pot before pregnancy have approximately the same odds for preterm birth as moms who develop preeclampsia.

How much weed? How frequently were these women smoking? The study doesn't say. And this has some doctors saying hey, wait a minute.

"I always advise caution when interpreting studies like these. First of all, there is a very good chance that anything we study can be associated with a specific outcome just by statistical chance; second, being associated with something is not the same as causing it," says Dr. David Fay, a family physician from Waukesha, Wisconsin.

For example, says Dr. Fay, a recent study showed that women who had fewer prenatal visits were more likely to deliver preterm. "When you think about it, however, it makes sense that the woman who delivers at 32 weeks won't be coming in for her last four or five prenatal visits because she's already delivered!" In other words, maybe the moms who smoked pot before pregnancy had other traits in common, like a particular health condition or poor diets—and that's the real connection.

But others in the medical community don't think it's a good idea to give pot smoking too much of a pass. As Dr. Michael Wasserman, a pediatrician at the Ochsner Clinic Foundation in New Orleans, Louisiana, says about the possible connection, "It reminds one that our bodies do have 'memories' of how you have treated yourself."

So how do you treat yourself right?

"Eat healthy, take prenatal vitamins, exercise as tolerated, and stay away from alcohol and drugs," advises Dr. Wasserman.

And this includes staying away from marijuana. Though he's not of fan of how statistics are used in this study, Dr. Fay admits, "We know that cigarette smoking increases the risk of preterm birth, so I wouldn't really be surprised if smoking marijuana did as well."

What did you give up when you knew you wanted to have a baby?