This sheet is about exposure to marijuana in pregnancy and while breastfeeding. This information should not take the place of medical care and advice from your healthcare provider.
What is marijuana?
Marijuana, also called pot, weed, or cannabis, is a drug that comes from a plant called cannabis. Marijuana is typically smoked (inhaled) or eaten (edibles). The main active chemical in marijuana is delta-9-tetrahydrocannabinol (THC), which is what causes you to feel high. Another major component of marijuana is cannabidiol (CBD).
The U.S. Food and Drug Administration (FDA) advises against the use of CBD, THC, and marijuana in any form during pregnancy or while breastfeeding.
What do we know about cannabidiol (CBD)?
There are no studies looking at the use of CBD during pregnancy or while breastfeeding. CBD can be found in many products such as coffee, chocolate, supplements, tinctures, cosmetics, lotions, suppositories, and bath salts. CBD products labeled as “THC free” may actually contain a measurable amount of THC.
How much is known about the effects of marijuana on a pregnancy?
It is hard to study marijuana use during pregnancy. Marijuana contains about 400 different chemicals, and some marijuana preparations can be contaminated with other drugs, pesticides, and/or fungi. Most of the older studies focus on people who inhale marijuana, not ingest (eat or drink) it. Eating or drinking products with marijuana in them might lead to higher levels of marijuana in the body.
The THC in marijuana has become more potent (stronger) over the years. Studies done years ago on marijuana with lower THC levels may not accurately reflect the possible risks for current marijuana users. Some people who use marijuana during pregnancy may have other risk factors such as using alcohol, tobacco, or other drugs, medical conditions, and/or lack of prenatal care. It can be hard to collect correct information on how much and how often marijuana is used.
I use marijuana. Can it make it harder for me to get pregnant?
Long-term use of marijuana might affect the menstrual cycle, which could make it harder to get pregnant. The effects on fertility appear to go away when marijuana use is stopped, or once a person develops tolerance to the drug.
I am using marijuana, but I would like to stop before becoming pregnant. How long could it stay in my body?
People eliminate drugs at different rates. The way marijuana is used (inhalation, ingesting, topically), how often it is used, and how much is used can affect how long its metabolites can stay in the body. For some people, it might take up to 30 days for the THC metabolite to be gone from the body.
Does using marijuana increase the chance for miscarriage?
Miscarriage can occur in any pregnancy. Based on the studies reviewed, it is not known is using marijuana increases the chance for miscarriage. One study found that people who used marijuana were at an increased risk of having a miscarriage. Other studies have not confirmed this finding.
Does using marijuana increase the chance of birth defects?
Every pregnancy starts out with a 3-5% chance of having a birth defect. This is called the background risk. Most studies have not found an increase in the chance for birth defects in pregnancies exposed to “occasional” marijuana use. A few studies have suggested a small increase in the chance for gastroschisis (a rare birth defect in which the infants’ intestines stick out of an opening in the abdominal wall).
Does using marijuana in pregnancy increase the chance of other pregnancy-related problems?
Smoking marijuana may increase carbon monoxide levels in the blood, which can lower the amount of oxygen the baby receives. Some studies have suggested that among people who smoke marijuana regularly, there is an increased chance for pregnancy complications such as preterm delivery (birth before week 37), low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth), small length, small head size, and stillbirth. Babies that are born preterm or with low birth weight can have higher rates of learning problems or other disabilities. In some studies, a dose-response relationship was seen, meaning the more a person smoked, the higher the chance for these complications to occur. It is not known if these complications are caused by the marijuana use itself, or if the people in these studies had other risk factors (such as smoking cigarettes).
If I use marijuana throughout my entire pregnancy, will it cause withdrawal symptoms in my baby after birth?
Some newborns who were exposed to marijuana during pregnancy have been reported to have temporary withdrawal-like symptoms, such as increased tremors, changes in sleeping patterns, and crying. These symptoms usually go away within 30 days.
Does using marijuana in pregnancy affect future behavior or learning for the child?
Several studies have followed children exposed to marijuana during pregnancy, and suggested these children are at higher risk for problems such as impaired executive functioning (the ability to plan, focus, remember, and multi task), impulsivity, hyperactivity, aggression, depression, and anxiety. These children were also more likely to have problems with the ability to pay attention, memory, and academic achievement. When these children reached adulthood, some studies suggest that they are more likely to misuse substances themselves. One study found an increased risk for autism spectrum disorder when marijuana was used during the pregnancy. These issues have been reported more often in children of “heavy” marijuana users (users who smoked one or more marijuana cigarettes per day). The evidence is not conclusive and some studies reported conflicting results.
Professional organizations such as the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists advise that people who are pregnant avoid using marijuana.
Breastfeeding while using marijuana:
THC has been found in breastmilk. In one study, researchers found that breastfed babies ingest approximately 2.5% of the dose of THC used by the person who is breastfeeding. The amount of time THC remains in the milk ranges from 6 days to 6 weeks. Available research has not proven clear health concerns when a person who is breastfeeding reports smoking marijuana on a daily basis, except for a possible delay in motor development (learning to crawl and walk on time).
Marijuana can affect prolactin (a hormone that tells the body to make milk). There is a concern that frequent marijuana users may see a negative effect on the quality and amount of milk they produce.
Other factors to think about are possible legal issues if a baby that is breastfed tests positive for marijuana, the fact that there may be other contaminants (mentioned above) in the marijuana that could expose the baby to other substances, and the possibility that the baby could be directly exposed to second-hand smoke.
Most professional organizations such as the American Academy of Pediatrics, the Academy of Breastfeeding Medicine, and the American College of Obstetricians and Gynecologists advise that people who are breastfeeding avoid using marijuana. Be sure to talk to your healthcare provider about all your breastfeeding questions.
If a male uses marijuana, could it affect fertility (ability to get partner pregnant) or increase the chance of birth defects?
Marijuana use may lower sperm count (the number of sperm) and motility (the ability for those sperm to reach the egg). These factors could make it harder to conceive a pregnancy. These effects are thought to be temporary, and sperm function is expected to return to what it was once marijuana use is stopped. In general, exposures that fathers or sperm donors have are unlikely to increase the risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.
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OTIS/MotherToBaby recognizes that not all people identify as “men” or “women.” When using the term “mother,” we mean the source of the egg and/or uterus and by “father,” we mean the source of the sperm, regardless of the person’s gender identity.