Marijuana & Pregnancy - Is it Safe?

By Sonia Alvarado, Senior Teratogen Information Specialist, MotherToBaby CA

Marijuana has been in the news a lot lately and for marijuana users who have had to smoke in illegally, it appears societal attitudes about pot smoking may be changing. Twenty states have laws legalizing some form of marijuana use. Two states, Colorado and Washington, have legalized its recreational use. In an interview, the NFL Commissioner seemed to leave open the possibility that medicinal use could be considered for NFL players if there was scientific evidence that it was helpful to treat injuries and pain. Even President Obama has said that he doesn't believe marijuana is any more dangerous than alcohol. Marijuana is currently listed as a Schedule I drug. Other Schedule I drugs include heroin, lysergic acid diethylamide (LSD), 3,4-methylenedioxymethamphetamine (ecstasy).

What The Research Shows Us

According to studies, pregnant women who use illicit substances are more likely to use marijuana compared to other drugs. This is often due to the belief that marijuana is less harmful to the developing embryo and fetus, compared to other drugs such as cocaine or heroin.

Marijuana is Cannabis. The delta-9-tetrahydrocannabinol (THC) in the Cannabis plant produces the psychoactive effect or "high." Marijuana can be smoked in a joint, inhaled through a bong or vaporizer, eaten in food and teas/beverages, used in tinctures, and topical balms. Smoking and ingestion exposes the user to THC, producing the high. When smoked in a joint, the user is exposed to carbon monoxide from the burning of the leaf as well as tar, which can stay behind in the lungs.

Marijuana use during pregnancy has been studied since the 1960's. Like all studies, there are weaknesses that have been pointed out. For example, asking women about past drug use may not be the most accurate way to make a connection between the dose of the drug and the adverse effects because the women may have forgotten. Also asking women to volunteer information about drug use, which they may fear disclosing even in a confidential setting, may make it difficult to know how frequently pregnant women use drugs overall. Still, a number of experts have reviewed hundreds of reports in humans and animals. At least to this point, the studies do not support an association between marijuana smoking and birth defects. One large study of 12,825 interviews done after delivery, did not find a statistical association between marijuana use and birth defects.

However, the studies also show that marijuana is not risk free. Studies have reported associations between marijuana smoking and growth restriction and lower birth weight, particularly in women who keep smoking through delivery or late in pregnancy. An Australian study of almost 420,000 live births reported a higher risk for neonatal intensive care admission for newborns exposed prenatally to pot. Also, there are reports of abnormal responses or behaviors in the newborn period and this suggests a toxicity or withdrawal. The symptoms include exaggerated and prolonged startle reflexes (sleep cycle disturbances with high-pitched crying.) In a Brazilian study, exposed newborns were "more irritable and less responsive to calming, cried more during the examination, and exhibited more jitteriness and startles than the non-exposed neonates." Pregnant women who smoke daily and/or through delivery, have a higher risk for complications in their pregnancy compared to women who quit in the first trimester.

Researchers have attempted to assess the long-term effects of prenatal marijuana exposure. Studies of 3, 10 and 14-year old prenatally exposed children suggest that the prenatal exposure to high doses of marijuana may make it harder for children to learn and may affect their emotions (increased aggression) and increase depression symptoms. Studies are needed to assess which prenatally exposed children are most at risk. Its important to note that the children in these studies often have had prenatal exposure to other drugs as well, struggles with poverty and other life challenges, making it difficult to know that the findings are due to a single drug exposure.

So Where Does Marijuana Rank Compared To Other Drugs?

Alcohol: Specific to use during pregnancy, marijuana is not alcohol. Alcohol is still the drug with the highest risk and the widest range of birth defects, including physical, mental and behavioral. Alcohol is a drug with the highest use throughout the world, easy legal access, and social acceptance.

Cocaine: Cocaine, by comparison, is associated with a small risk for birth defects, and a higher risk for admission to newborn intensive care for withdrawal and toxicity. Additionally, cocaine is associated with prenatal growth retardation, lower birth weight, shorter length, and smaller head circumference. Studies suggest the effects on height extend into childhood.

Heroin: Heroin has not been associated with an increased risk for birth defects, however, is associated with a higher risk for withdrawal and admission to newborn intensive care and sudden infant death syndrome.

Bottomline: Snuff Out Smoking It

Clearly, marijuana use in pregnancy is not preferable, nor less risky, compared to most other drugs when a side-by-side comparison is made. Changing societal attitudes doesn't change the fact that the developing embryo (and fetus) is dependent on the mother for oxygen, nutrients and a balance of hormones, chemicals and other substances to grow normally. Disrupting the normal fetal environment, through the introduction of marijuana or other recreational drugs, puts the pregnancy at risk in the short-term and possibly the long term as well.

Sonia Alvarado is a bilingual (Spanish/English) Senior Teratogen Information Specialist with MotherToBaby California, a non-profit that aims to educate women about medications and more during pregnancy and breastfeeding. Along with answering women's and health professionals' questions regarding exposures during pregnancy/breastfeeding via MotherToBaby's toll-free hotline, email and private chat counseling service, she's provided educational talks regarding pregnancy health in community clinics and high schools over the past decade.

MotherToBaby is a service of the international Organization of Teratology Information Specialists (OTIS), a suggested resource by many agencies including the Centers for Disease Control and Prevention (CDC). If you have questions about beauty products, medications or other exposures, call MotherToBaby toll-FREE at 866-626-6847 or visit MotherToBaby.org to browse a library of fact sheets and find your nearest affiliate. photo credit:MendezEnrique via photopincc