What does medical marijuana use actually do to a fetus?

By Lauren Gilger
Published: Thursday, January 18, 2024 - 1:18pm

Audio icon Download mp3 (11.45 MB)

The Arizona Department of Child Safety says it will no longer investigate reports of newborns who test positive for marijuana — as long as their parent has a medical marijuana card. The move came after an appeals court ruled in favor of a mother who used medical marijuana during pregnancy to curb severe nausea and vomiting. The decision said that kind of cannabis use is protected under Arizona’s medical marijuana law because it’s under a doctor’s advice. 

So, what does marijuana use do to a fetus? And how often do doctors in the Valley see use during pregnancy?

For more on all of that, The Show spoke with Dr. Krista LaBruzzo, a doctor specializing in addiction medicine at Banner Health. 

KRISTA LABRUZZO: You know, this has been something that I feel like has been very ongoing and something we've been studying and it's changed over time too. Because as you see, marijuana used to be mostly in leaf form, it used to be mostly smoked, and now we kind of have legalization where we have tons of different forms of marijuana or cannabis. And the biggest part that comes into play with that is the component of THC or tetrahydrocannabinol, which is that kind of active component. So we see much higher potency now, and so the studies we had from the ‘80s don't necessarily correlate with the potency that we're seeing right now.

So there are a couple of studies that kind of look at, “OK, any female with marijuana use during pregnancy, chronic, what do we see that happens with fetus and then later on with newborn and childhood and adolescence?” “What we do see is, we like have this natural endocannabinoid system in our body, is what it's called. So we naturally have a system that is very similar to THC, and so we get concerned when we have that natural system, what happens when we give exogenous THC? And what does that look like? Because not only is it a part of our immune system, it's a part of implantation, it's a part of pregnancy, it's a part of fetal development.

So what we see in the couple of studies, we do have from, you know, roughly the 2000s, we see that risks to baby in general, low birth weight, they may have NICU stays. They may be more stimulated, meaning more reactive to light and just, you know, a little bit more fussy just because of a withdrawal-like state. We also see that young kiddos even at a young age will have decreased verbal skills, and that adolescents are more likely to develop ADHD or issues with executive function and problems with substance use. So there are some things that we're seeing, but again, there's many confounders, meaning some of these mothers used other substances. Maybe there's low socio-economic status which is hard to get into programs and things like that. So there are other confounders but there's definitely concern.

LAUREN GILGER: So, I mean, I have been pregnant and I know that like, mostly what happens is you have lots of things that have not been studied in pregnancy, and so they'll say “We don't really know, so don't do it or don't use it. Don't take that medicine because we don't really know.” It sounds like this sort of falls in that category. Why is it so difficult to have studied this?

LABRUZZO: It's difficult because if you think about it, we can't do a randomized control trial. If there is risk that we're aware of, which we look at these longitudinal studies, it's unethical to be like to tell someone, “Ok, you're going to smoke marijuana, you're not,” and have that potential of having these issues with, with the fetus or with the newborn. And so we have to look longitudinally and a lot of times it's retrospective meaning, you know, we're asking moms to look back in pregnancy, tell us how much they were using or smoking, were they using anything else? And sometimes, you know, looking back, we're just not as confident, or you know, it's just not correct.  You don't remember everything. And so it becomes a little difficult to kind of look at those fine details.

GILGER: So how do we know how common it is that a pregnant person will be prescribed even something like medical marijuana to treat something like morning sickness? I know that exists, right?

LABRUZZO: Yeah, it does, and, you know, here in the Valley, I would say it's very uncommon. I have not seen it, any prescriber. And that's only because we do have medications for morning sickness that are safer, that we know are safer. So it would be very rare. And we also just don't have good data that says, “Hey, does this actually help?” “What's the risk versus benefit here for people?” I will say anecdotally. There are studies that say pregnant women say marijuana use does help their morning sickness, but we just don't have great data that kind of shows that objective data, whether we do have less vomiting, we do have less hyperemesis, things like that. Since we do have some safe medications, those are first line, definitely.

GILGER: So what do you see most often when it comes to infants who are born with drugs in their system? Is it often marijuana or is it often, you know, marijuana and something else?

LABRUZZO: I would say it's often marijuana and something else. And you'll see, you know, we have patients that use cannabis or use nicotine. They're more likely to use other substances as well. So I would say most of the time it's marijuana, nicotine, especially as, you know, we are in this sort of, we've been in an opioid epidemic for quite a while. I see a lot of fentanyl as well and babies undergoing neonatal abstinence syndrome. And so them having a withdrawal from that, which can complicate, you know, other withdrawals from other substances.

GILGER: So, what does that look like in an infant when they are, you know, withdrawing from drugs? I think that's something you don't normally associate with an infant, right?

LABRUZZO: It depends on what the substance is, and so basically, withdrawal looks like whatever the drug does withdraw is the opposite of that. So if a drug is what we call a downer, the withdrawal is gonna be something that looks very, very stimulated. So in babies with opioid withdrawal, they're gonna have increased fussiness, this kind of high pitched cry. They may have diarrhea, they may have a little bit of tremors and things that all look the opposite of use. It can be complicated too by other substances. You can have polysubstance use in a pregnant patient and you can have withdrawals in babies for sure, that can kind of complicate and be multi-polysubstance use.

GILGER: So the Arizona Department of Child Safety is no longer going to investigate mothers of infants that test positive for cannabis, right? What do you make of a decision like that? Do you think there should be a punitive side to this?

LABRUZZO: It's so difficult honestly, when it comes to substance use in pregnancy and kind of, in general how we treat substance use is very punitive just across the board, whether it's pregnancy, whether it's someone that isn't pregnant, the way we do treat substance use disorder is very punitive. And so, you know, I always tell my patients, especially when they come in that “Hey, for our policy, this has to be, you know, reported once baby is born.” But as long as we have recovery and treatment options, and there's low risk to baby, let's hopefully just make sure that this is a nuisance and not something that we have to worry about.

And it's difficult when we start to pick and choose which substances we decide to investigate and which ones we don't. I will say that hospitals in general do a really poor job of screening for substance use disorder. A lot of times it's up to the staff to kind of say, “OK, I'm concerned, let me do a urine drug screen,” and that can cause a lot of ethical dilemmas where we're over screening our lower socioeconomic status patients, which we see all the time. And so I think it becomes really tricky when we start to pick and choose which substances we're going to investigate and that's how I kind of feel with cannabis use as well. We do know that there is some harm to baby that can happen. Does that mean that that child should be taken away from their parents? No, it's just another opportunity to engage someone in recovery or healthier use and what that looks like.

More stories from KJZZ

Science The Show Health + Medicine Marijuana