There’s not a lot of data on the effects of marijuana on a growing baby – but the research that has been done is enough to make you think twice about using pot during pregnancy
What’s the Concern?
Some midwives recommend occasional marijuana use during pregnancy to treat morning sickness or decrease anxiety. After all, eating healthy foods to gain weight and staying stress-free are essential to having a healthy pregnancy. But since the active drug in marijuana (tetrahydrocannabinol, or THC) changes all sorts of processes in the adult body – from heart rate to brain function – it’s reasonable to think that it also might affect a growing baby. Some research has shown that when marijuana is smoked or ingested by a pregnant woman, THC may cross the placenta and enter a fetus’s bloodstream.
Researchers are ultimately unsure of the exact effects of THC on a growing baby. The challenge with many studies on marijuana use is that they rely on questionnaires. If women are worried their answers may not be anonymous, they might deny smoking pot even when they have. What’s more, researchers have repeatedly noted that women in their studies who smoke pot during pregnancy often also smoke cigarettes. This complicates the statistics, since any negative effects on their children could be caused by tobacco and not marijuana use.
Little Evidence of Birth Defects?
A 2014 study that looked at more than 20,000 U.S. birth records from 1997 through 2005 found that the odds of a baby being born with anencephaly, a type of neural tube defect that causes serious brain malformation, were almost doubled (although still extremely rare) among babies born to mothers who reported smoking marijuana. But many other studies, including one analyzing more than 12,000 U.S. birth records in the 1980s, have found no statistical link between pot smoking and any birth defects. In general, health care practitioners agree that marijuana doesn’t directly cause physical birth defects.
…But Some Effect on Pregnancy and Baby’s Long-Term Health
What studies have shown more conclusively is that daily or weekly marijuana use may make your pregnancy more high-risk. For example, a 2011 Australian study of almost 25,000 women concluded that babies born to mothers who used marijuana were twice as likely to end up in the neonatal intensive care unit (NICU) compared to other babies.
What about long-term effects? A few studies have found that after 3 years of age, children born to marijuana-smoking mothers score slightly differently on cognitive and behavioral tests compared with other babies. A decade-long Canadian study found that at 4 years old, children born to mothers who used marijuana on a daily basis during pregnancy scored lower on memory tests, though there was no impact on overall intelligence scores. At age 10, kids had a slightly increased risk of hyperactivity, inattention and impulsivity.
Scientists who have turned to mice to understand the effects of THC on development showed in early 2014 that developing mice exposed to THC had altered connections between cells in their brain. They think this could explain why exposure to THC during pregnancy can leave children with lasting cognitive and memory changes.
What This Means for You
So is it okay to smoke or eat marijuana during pregnancy? Like many decisions, it comes down to weighing the risks and benefits. While using marijuana doesn’t appear to cause birth defects, there may be a chance it could make you go into labor early or possibly even effect your child’s brain development. The reality is, it’s virtually impossible to design a reliable study to test the effects of marijuana during pregnancy (no researcher would knowingly put a human baby at the risk of potential harm!), so we’ll likely never have definitive research pinpointing any short- or long-term effects of prenatal pot use on fetal development. Which means to be on the safe side, you’re best avoiding pot while you’re expecting.
If you’re looking for alternate ways to treat morning sickness, ask your health care provider for suggestions – there are natural remedies safer than marijuana and FDA-approved drugs. Depending on the nature of your anxiety, your doctor can recommend a combination of therapy and, if necessary, medication that’s safe for you and your baby.
If you do use marijuana during pregnancy, make sure you still visit the doctor regularly. Never skip appointments because you’re worried about revealing your drug use; your doctor should be your partner in ensuring your baby’s health. Getting proper prenatal care – which also means being honest with your practitioner about how often you use – is the best way to ensure your baby gets the best start to life possible.