Marijuana During Pregnancy: Is It Safe?
July 26, 2024
A growing number of women report using marijuana during their pregnancy. As recreational marijuana use rises, some dispensaries are recommending it as a remedy for morning sickness. (There's no medical evidence it does, and OBGYNs don't recommend it.) And in the past decade, the percentage of Americans using medical marijuana has more than doubled, and state-level recreational legalization has become increasingly common.
But is smoking marijuana while pregnant worth the risk?
How Does Marijuana Impact A Developing Baby?
What you eat, smoke and drink during pregnancy and after birth passes to your baby through your placenta and breastmilk. The chemical THC, found in marijuana, also crosses the placenta from the mother to the baby's bloodstream. The drug exerts its effects by stimulating so-called cannabinoid receptors. And fetal cannabinoid receptors start to develop in the first trimester.
What Are The Dangers Of Smoking Marijuana During Pregnancy?
Smoking marijuana while pregnant does have health effects on your baby.
"There's a common misconception that because [marijuana] is a plant, it's safe," said Dr. Nora Volkow, director of the U.S. National Institute on Drug Abuse.
Researchers in a study published last December in the Journal of the American Medical Association looked at low birth weight, pregnancy-related high blood pressure, stillbirth and preterm birth among women who used marijuana while pregnant.
Weed exposure was associated with a 1.5-fold increase in risk. About 26% of pregnant marijuana users experienced an unhealthy pregnancy outcome, compared with 17% of those who didn’t use weed.
Also, higher levels of cannabis exposure over the course of pregnancy were associated with higher risks, researchers said.
The greater risk seen at higher levels is concerning given the high amount of THC – weed’s intoxicating chemical – found in newer cannabis products.
Risks of marijuana on your baby
With marijuana use in pregnancy, your baby may also be more likely to have:
- A lower birth weight. The association between weed use and low birth weight was the strongest, researchers said.
- Abnormal sleep patterns, tremors and prolonged and exaggerated startle reflexes as an infant
- Higher risk of cigarette and marijuana smoking as a teenager
- Higher rates of behavior problems or problems learning
- Higher rates of mental health problems, including psychosis
There may also be a higher risk of some birth defects, stillbirth or miscarriage, premature birth and admission to the Neonatal Intensive Care Unit (NICU). A study in the Journal of the American Medical Association reviewing more than 660,000 pregnancies found the rate of preterm birth among reported cannabis users was significantly higher than nonusers - about 12%.
Growing research is showing that THC may change the way your baby's brain grows and develops. In fact, the Surgeon General issued a health advisory on marijuana use among pregnant women.
"No amount of marijuana use during pregnancy or adolescence is known to be safe," the Surgeon General's advisory on marijuana use during pregnancy says. "Until and unless more is known about the long-term impact, the safest choice for pregnant women and adolescents is not to use marijuana."
(You can read the full advisory here.)
"Years of research have proven that alcohol prevents normal development and growth of babies' brains," said Pamela Lynch, MD, who practices family medicine/obstetrics at Franciscan Physician Network Mooresville Family Care. "This was the #1 cause of development delays in children until we had enough proof to convince moms that they were permanently harming their children. You don't want your child to be part of the data showing the negative effects of marijuana in 20 years."
How Does Marijuana Use Affect Your Child?
Children who have been exposed to marijuana may demonstrate lower levels of:
- Verbal reasoning and memory
- Language comprehension
- Memory
- Reading
- Executive functioning tasks, including impulse control and problem-solving
Older children and teens who were exposed to marijuana show higher rates of:
- Depression
- Substance abuse
- Problem behaviors
Other Health Risks Of Marijuana Use During Pregnancy
Smoking marijuana while pregnant also exposes your baby to carbon monoxide (5 times more than with cigarettes), which lowers the amount of oxygen available in the baby's bloodstream.
Second-hand smoke from marijuana may also impact your baby's long-term health.
Is Medical Marijuana Safe For Pregnant Mothers?
Medical marijuana is not regulated or approved by the Food and Drug Administration nor is it recommended by the American College of Obstetricians and Gynecologists. Talk to your prenatal care provider about safer options if you are pregnant and are considering smoking marijuana to help morning sickness or if you use marijuana for medical or recreational purposes.
Any marijuana use can affect your ability to think clearly, stay alert, make good decisions and respond to the needs of your baby. Marijuana use includes:
- Smoking marijuana, including dabs
- Eating and drinking marijuana in any form
- Using vaporizers
- Eating or smoking wax or hash
- Any other methods, including creams or lotions
Using marijuana can alter your judgment and put you at a higher risk for dizziness, putting you at risk of injury and falls, which can be harmful for the mother and baby.
Other health risks of smoking marijuana include:
- Damage to your lungs
- Lowered level of oxygen in your body, which increases the risk of breathing problems
- Increase in anemia
Additional risks during pregnancy
A study published this week in the journal JAMA Internal Medicine found that pregnant women who used marijuana had higher odds for gestational hypertension, preeclampsia, weight gain that goes beyond recommended levels and a condition known as placental abruption (when the placenta separates from uterine wall).
For example, using marijuana raised a pregnant woman's odds for gestational hypertension (high blood pressure occurring while pregnant) by 17%, and her odds for an even more dangerous blood pressure condition, preeclampsia, by 8%, researchers reported.
The link to gestational hypertension was a dose-response relationship: the more often a woman used cannabis, the higher her likelihood of high blood pressure during her pregnancy.
Women who used marijuana also faced a 19% higher odds for placental abruption, which can jeopardize the flow of oxygen and nutrients to the fetus.
Marijuana use also upped the odds that a woman would gain weight during her pregnancy at a rate that was either higher or lower than that recommended.
There was one outlier to the findings: Women who used marijuana while pregnant appeared to have a slightly lower risk of developing gestational diabetes.
What Is Cannabis Use Disorder?
Cannabis use disorder may be diagnosed when a person has more than one sign of problem use -- such as strong cravings to take the drug, withdrawal symptoms, and continuing to use it even when it's causing problems at work or in relationships.
Based on medical records, few pregnant women in the study had a marijuana use disorder. But the rate increased over time -- from just under 3 per 1,000 in 2001, to almost 7 per 1,000 in 2012.
What Are Risks For Babies Of Moms With Cannabis Use Disorder?
Babies born to moms with cannabis use disorder were more likely to be born early and underweight, versus babies whose mothers did not have the disorder but were similar in terms of race, education and overall health.
They were 6% more likely to be born preterm and 13% more likely to be either underweight or small for gestational age -- a sign of growth restriction in the womb.
The risks were greater when moms used both marijuana and tobacco. But pot use was a risk factor regardless of cigarette smoking, the researchers said.
And while few babies died during the first year of life -- fewer than 1% -- those whose moms used marijuana heavily had a 35% higher risk.
What Are The Effects Of Smoking Marijuana While Breastfeeding?
Smoking marijuana while breastfeeding is not safe for your baby. THC builds up in breast milk as much as 8 times higher than in a mother's bloodstream. THC is then absorbed into a baby's bloodstream and can be stored in a baby's fat tissue for weeks to months. THC also gets into a baby's brain and can make a baby extra sleepy and not feed very well. It can also cause delays in a baby's development.
Marijuana has also been shown to contain other dangerous substances, including toxins from pesticides, herbicides and fertilizers. These chemicals can also transfer through the breast milk.
Are Edibles A Safer Alternative to Smoking?
People often believe that "edibles" are a safer way to consume marijuana. But while there's no smoking involved, Volkow said edibles have their problems.
"It takes longer for the effects of edibles to emerge, so people may keep taking more," she said. They can end up consuming a THC dose large enough to land them in the emergency room.
How Many Women Use Marijuana During Pregnancy?
A U.S. National Institute on Drug Abuse study found that between 2002 and 2017, the number of U.S. pregnant women who said they'd used marijuana in the past month doubled -- from about 3.5% to 7%. Of women who use pot during pregnancy, 80% also smoke cigarettes. The new study, published April 22 in the journal Addiction, was large, looking at data from 4.8 million births in California. That gave the researchers a chance to zero in on women who used marijuana regularly but not tobacco.
Need Help Quitting?
Franciscan Health offers a variety of programs to help with those wanting to stop marijuana use. Services include comprehensive assessment, individual and group therapy, and Intensive Outpatient Program, depending on your goals and current needs.
For 24 hour or emergency assistance, call the Substance Abuse and Mental Health Association (SAMHSA) National Helpline at 1-800-662-HELP (4357).
Learn More About Marijuana's Impacts
Understanding marijuana's health impacts on your baby is crucial, but it's important to see how it fits into the bigger picture of your health, too. Get the facts on how marijuana can affect your overall health.
