But we are accumulating evidence that marijuana is probably not a great idea to use if youre pregnant.

Children who were exposed to marijuanain uteroare more likely to have cognitive and behavioral problems later in life.

The experts I spoke with absolutely did not recommend smoking weed while youre pregnant.

If you want a yes or no, theres your no.

So here are the details.

Marijuana Affects Brain Development

The best known marijuana chemical istetrahydrocannabinol(THC).

Its the main psychoactive component, the part that gets you high.

THC is also fat-soluble, and can end up being incorporated into your body fat.

This of course is the whole essence of the brain, she says.

One neuron connects to the next neuron, which connects to the next.

And the more marijuana the brain is exposed to, the greater the effect on those connections.

Its well established that THC interferes with the way brain cells connect to each other.

But What About Other Studies?

The Jamaican studies were also small, and didnt follow the babies as they grew up.

It concluded that marijuana use during pregnancy is not an independent risk factor for adverse neonatal outcomes[.

That would be nice, right?

Thechapter on pregnancy and breastfeedingbreaks down what we know according to how strong the evidence is.

In other words, the evidence is pretty good but not ironclad.

There is also insufficient evidence to link marijuana use during breastfeeding with SIDS.

Finally, theres another category formixedevidence, which means that some studies say yes and others say no.

Most birth outcomes (preterm birth, low birth weight) fall into this category.

You cancheck out the full reportto read about which studies the advisory committee used and how they analyzed them.

Not All Weed Is the Same

Why are these studies all coming to different conclusions?

You might be a different age or income level than moms who quit toking or who never started.

And then theres the question of the weed itself.

So its possible that using marijuana during pregnancy today is more harmful than it was back in the 1980s.

Theres also a lot of variety in what it means to use marijuana.

How often do you use it?

Do you smoke it, vape it, or eat it?

How far along are you in your pregnancy?

(Different parts of the brain and nervous system mature at different times.

Marijuana also contains dozens of psychoactive substances, of which THC just happens to be the best studied.

We know very little about what the others do.

Its hard to make any kind of medical statement about [all] marijuana, he says.

Its not like making a medical statement about ibuprofen.

But women douse marijuana in about 5 percent of pregnancies.

Many use it to manage nausea.

And anyone living through the months of hell known ashyperemesis gravidarumhas a serious risk/benefit calculation to make.

I dont think I would have made it through without cannabis.

Thats just not true, she says.

So its important to double-check your provider understands the benefitsandthe risks.

We dont know if there are other effects of marijuana that just havent been studied yet.

We cant go back in time to re-start long term studies, but we can support better studies now.

So far, thats not the case.

We also dont even know all the questions we should be asking.

Theres still alotwe dont know.