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Is It Safe To Smoke Marijuana During Pregnancy?
Is It Safe To Smoke Marijuana During Pregnancy

Smoking marijuana is not recommended during pregnancy. But some women are starting to consider marijuana to help make their pregnancy easier.

For most expectant mothers, avoiding drugs and alcohol while pregnant is the obvious choice. However, experts are not entirely clear on the risks of using marijuana during pregnancy.

Morning sickness and anxiety are very common for pregnant mothers, and a small number of women swear by marijuana’s ability to alleviate their symptoms.

Doctors and scientists aren’t as quick to suggest using marijuana during pregnancy. While research on the subject is limited, some studies suggest that marijuana can have harmful effects on the fetus.

Overall, the use of marijuana during pregnancy seems to be somewhat less risky than other drugs. But it is still considered a significant risk. As a result, marijuana should be avoided during pregnancy and breastfeeding.

How Common Is It?

Pregnant woman rolling up a joint
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To most people, the idea of using marijuana while pregnant is out of the question. But to others, marijuana is a necessary medicine that provides much-needed relief.

Estimates of how many women smoke marijuana while pregnant range from 4% of all expectant mothers to 30% in some inner-city communities.

Morning sickness is a common symptom in early pregnancy, with around 70% of women being affected by nausea or vomiting. For some, it can be quite severe.

Some women use marijuana to curb their morning sickness, allowing them to finally eat and get much-needed nutrients for themselves and their developing babies. Marijuana is well-known for its ability to reduce nausea and increase appetite.

Mothers have also reported using marijuana to help with anxiety, stress, emotional stability, and pain associated with the pregnancy.

It is also possible that some women unknowingly smoke marijuana while they’re pregnant, because they are unaware that they are pregnant.

Does Exposure to Marijuana Harm Babies?

Does Exposure to Marijuana Harm Babies
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Evidence suggests that marijuana may negatively affect babies. Smoking marijuana during pregnancy is correlated with premature birth and low birth weight. It may also affect children’s learning and memory, intelligence and behaviour.

Although these studies are correlational, experts believe that the use of any drugs or alcohol during pregnancy can lead to health problems for both the mother and baby.

Tobacco, alcohol and other drugs can affect a developing fetus in a number of ways.

For example, fetal alcohol syndrome can occur when a mother drinks alcohol while pregnant. This can result in abnormal facial appearance, small size, low intelligence and behavioural problems in children.

The effects of marijuana on a newborn are less severe than alcohol, but there are still a number of ways that marijuana could affect a developing baby.

Premature Birth

Mothers who smoke marijuana during pregnancy are reported to be more likely to give birth prematurely.

This means that babies have less time to fully develop before they are born. Babies born prematurely can have serious medical complications such as brain, heart, and breathing problems.

Low Birth Weight

Some studies have found that babies born to mothers that smoked marijuana during pregnancy are more likely to have a low birth weight.

Other studies stress that there is insufficient evidence to say with certainty that marijuana causes low birth weight or premature birth.


One study showed that exposure to marijuana during the first and second trimester of pregnancy correlates with low IQ in 3-year-old children. Another study showed similar results at age 6.

Nevertheless, there is insufficient evidence to say whether these results are accurate or tell the whole story.

Behavioural problems

In one study, children born to mothers that used marijuana during pregnancy showed behavioural problems at age 10. The children were more hyperactive, impulsive, and disobedient. They also suffered from attention deficits (like in ADHD).

However, these problems did not show up before the age of 10.

Correlation vs. Causation

Correlation vs. Causation
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Many studies seem to report that marijuana use during pregnancy can lead to negative effects. These negative effects include low birth weight, preterm birth and cognitive problems in later life.

But most studies of marijuana use during pregnancy are correlational. This means they can’t prove whether it’s marijuana, or some other trait that women who smoke marijuana during pregnancy share, that causes the negative effects.

These studies also rely on measuring outcomes after a baby is born. This means it is very difficult to say for sure that these negative effects are directly related to marijuana itself.

Tobacco use and socioeconomic status are two traits that may affect results of studies on marijuana and pregnancy.

Women who consume marijuana during pregnancy are also more likely to consume tobacco while pregnant. The effects of tobacco on a developing fetus are known to cause serious health problems.

Women in lower socioeconomic conditions are also more likely to smoke marijuana during pregnancy. These mothers will have fewer resources to care for their child after they are born. This may explain some of the findings of lower intelligence and behavioural problems in these children.

One study found that the negative effects of using marijuana in pregnancy seemed to disappear after controlling for tobacco use and socioeconomic status.

Limitations of Studying Marijuana and Pregnancy

Limitations of Studying Marijuana and Pregnancy

There are many limitations to studying the effects of marijuana use on a developing fetus. This makes it challenging to correctly estimate the risks of marijuana use during pregnancy.

Strength of Marijuana

Most research on the effects of marijuana during pregnancy was done decades ago, when the potency of strains was much lower. The effects of smoking marijuana during pregnancy could be stronger now than compared to these older studies.


No studies have looked at the effects of different compounds in marijuana on developing babies.

In some U.S. states, the non-psychoactive CBD is already approved as a safe medication for a variety of disorders. But whether certain compounds can actually help pregnant moms and not harm the developing fetus is still unknown.


For ethical reasons, researchers can’t ask mothers to smoke marijuana during their pregnancy and study the results.

Because of this, studies on marijuana in pregnancy cannot be put under proper scientific rigor.


Due to marijuana’s illegal status, women may be afraid of the legal repercussions of admitting to their marijuana use.

Even where marijuana is legal, there is a strong stigma associated with drug use during pregnancy. So marijuana use in pregnancy is probably under-reported, and this may affect the results of studies.

Can Marijuana Improve Outcomes For Babies?

Can Marijuana Improve Outcomes For Babies
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It is very unlikely that babies born to mothers that used marijuana during pregnancy will show any benefit from exposure to the drug.

Nevertheless, many people cite a 1994 study known as the Jamaica Study when arguing that marijuana may actually benefit babies.

In this study, researchers looked at 1-month-old babies born to Jamaican mothers who used marijuana heavily while pregnant. These babies were more alert, less irritable and overall easier to care for than babies born to mothers who did not consume marijuana.

The results of this study were intriguing, but the authors concluded that it was not the marijuana that led to better outcomes for the babies.

They determined that it was actually social and cultural factors that were responsible for the benefits seen in the babies.

The lead author of the study, Dr. Melanie Dreher, explained in a phone interview:

“[We] attribute it to rather the social differences between the marijuana-using mothers and the non-using mothers. Even though they were the same, they were matched for age and socioeconomic status, but there were differences in the lifestyles of the ingesting and non-ingesting mothers that we believe accounted for the differences. For example, many of the using mothers also were vendors of ganja and so they were pretty much at home most of the time in that neonatal period, so they were quite attentive to their babies.”

Dreher added that her study doesn’t “okay” the use of marijuana during pregnancy. But the study did reveal that there were no adverse effects seen at 1 month of age.

The Safest Bet: Avoid Substance Use During Pregnancy

The Safest Bet: Avoid Substance Use During Pregnancy
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Developing babies are very sensitive to foreign substances. THC and other active ingredients in marijuana are known to cross the placenta and directly affect the fetus.

Even though studies on marijuana are limited, it’s always best to use caution when it comes to any kind of substance during pregnancy.

Anecdotal evidence suggests that marijuana can help with morning sickness, but it is important to remember that morning sickness tends to get better over time, even without the help of drugs.

Most doctors agree that there is no clear benefit of using marijuana during pregnancy, and numerous studies suggest that there are risks. Even if the studies were wrong, would it be worth the gamble?

Dr. Jennifer Blake, CEO of the Society of Obstetricians and Gynaecologists of Canada, stresses that mothers should make the best choices possible during this crucial time. Dr. Blake explained in an interview:

“When you’re pregnant, you’re making choices that your baby has no say in. These are critical developmental moments for your baby. It’s the time to do the very best that you can.”


Pregnancy can be difficult for many women, especially those suffering from morning sickness or other symptoms.

Stories of women that use marijuana to help ease their pregnancy are becoming more common, especially with the legalization of marijuana in some places.

Even though babies born to mothers who used marijuana while pregnant typically do not have serious health problems, the risks are still very poorly understood. These include possible behavioural and cognitive deficits.

Overall, using marijuana during pregnancy is considered risky and is not recommended. If you are thinking of using marijuana to treat morning sickness or other symptoms, consult with a health professional first.