Giving Birth with Confidence, Nutrition & Wellness

Pregnancy and Weed - What Do We Know?

Cara Terreri

A new study published shows that more people are using marijuana during pregnancy. With marijuana's increase in accessibility (it is now fully legal in 10 U.S. states plus Washington DC, and medically legal and decriminalized in a large majority of the remaining states), along with a list of medical benefits, it's not surprising to see an increase in its use, even during pregnancy, both for medical and non-medical purposes.

Since one of the hallmarks of pregnancy is sharing nearly everything with your developing baby, it's important to know as much as you can about marijuana's impact. In this article, I will share what we currently know about marijuana use during pregnancy and its affects according to some of the major health organizations. The data, unfortunately, is limited due to the fact that it is difficult to accurately study marijuana use during pregnancy. MotherToBaby, the nonprofit organization that reports on exposures during pregnancy and breastfeeding, explains why: 

Marijuana contains about 400 different chemicals, and some marijuana cigarettes may contain contaminants, such as other drugs, pesticides, or fungi. Some women who use marijuana may also use alcohol, tobacco, or other drugs at the same time. Women who use marijuana during pregnancy may also have other factors that can increase pregnancy complications, such as lack of prenatal care or an unbalanced diet. In addition, marijuana has become more potent (stronger), particularly in THC content over the past years. Many growers are focusing on sinsemilla. Sinsemilla refers to growing marijuana a certain way to get a more potent (stronger) marijuana product. Therefore, studies done years ago would, in theory, be looking at marijuana that was less strong than currently being used. Finally, information on the amount, frequency, and timing of marijuana use can be difficult to accurately collect.

What We Know About Marijuana Use During Pregnancy

From MotherToBaby:

  • In women, long-term use of marijuana may affect the menstrual cycle and lead to a reduction in hormones involved in reproduction and fertility. In men, an association with reduced sperm count has been seen. These side effects might make it harder to get pregnant. The effects on fertility appear to go away when marijuana use is stopped.
  • Most studies have not found an increase in the chance for birth defects among babies prenatally 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), and one study reported an increased chance for heart defects among babies prenatally exposed to marijuana. 
  • Some studies have suggested that among women who smoke marijuana cigarettes regularly, there is an increased chance for pregnancy complications such as: premature birth, low birth weight, stillbirth and small length, small head size, and death in the newborn period
  • Some newborns exposed to marijuana have been reported to have temporary withdrawal-like symptoms, such as increased tremors and crying. These symptoms usually go away within a few days.
  • Differences in brain activity, behavior, and sleeping patterns of infants and children exposed to marijuana in pregnancy have been reported in some studies. ... These problems have been seen more often in children whose mothers were “heavy” marijuana users (smoked one or more marijuana cigarettes per day). The evidence is not conclusive and some studies report conflicting results.

(Source and to read more.)

From the Centers for Disease Control (CDC):

  • The chemicals in marijuana (in particular, tetrahydrocannabinol or THC) pass through your system to your baby and can harm your baby’s development.
  • Some research shows that using marijuana while you are pregnant can cause health problems in newborns— including low birth weight.
  • Breathing marijuana smoke can also be bad for you and your baby. Marijuana smoke has many of the same chemicals as tobacco smoke and may increase the chances for developmental problems in your baby.
  • Some research shows marijuana use during pregnancy may make it hard for your child to pay attention or to learn; these issues may only become noticeable as your child grows older.
  • Separate from the direct, chemical effects of marijuana on a baby, use of marijuana may affect a mother’s ability to be able to properly care for her baby.

(Source and to read more.)

From the American College of Obstetricians and Gynecologists (ACOG):

  • When marijuana is smoked or eaten, the chemicals reach the fetus by crossing the placenta. Research is limited on the harms of marijuana use during pregnancy. But there are possible risks of marijuana use, including babies that are smaller at birth and stillbirth. Using marijuana also can be harmful to a pregnant woman’s health. The American College of Obstetricians and Gynecologists recommends that pregnant women not use marijuana.
  • Edible marijuana is processed differently in the body than marijuana that is smoked. Because edible marijuana is eaten and digested, the effects take longer to be felt. This leads some users to eat more marijuana to feel the effects more quickly. It is not possible to tell how strong the marijuana is before eating it. For these reasons, there is a higher risk of overdose with edible marijuana than with marijuana that is smoked.
  • Medical marijuana is no different than nonmedical marijuana. It is not safer. It has all of the harmful effects of nonmedical marijuana. It is important to let your ob-gyn or other health care professional know if you are using medical marijuana and to discuss other treatments you can try that are safe to use during pregnancy.
  • Marijuana exposure may disrupt normal brain development of a fetus.
  • Babies whose mothers used marijuana during pregnancy may be smaller at birth.
  • Research suggests an increased risk of stillbirth. It is not known if this is only because of marijuana use or due to use of other substances, such as cigarettes.
  • Some studies suggest that using both marijuana and cigarettes during pregnancy can increase the risk of preterm birth.
  • Children whose mothers used marijuana during pregnancy may have learning and behavioral problems later in life.
  • Marijuana can make people dizzy and fall. Falls can be dangerous for pregnant women. Marijuana also can alter your judgment, putting you at risk of injury. Smoking marijuana lowers your body’s level of oxygen, which increases the risk of breathing problems. Smoking marijuana also can damage your lungs. 

(Source and to read more.)

The consensus, despite having a lack of complete data, reveals that it is safer and healthier to avoid consumption/use/smoking/ingesting of marijuana during pregnancy. If you use medical marijuana, it's best to talk with your care provider and about all options and weigh the benefits and risks associated with each.