Expert Health Articles

Harmful Effects of Marijuana Use During Pregnancy and Breastfeeding

Jennifer Hohman, MD

Bluffton Hospital

It is common knowledge that smoking cigarettes and drinking alcohol can be harmful to an unborn baby. Unfortunately, many people do not realize how dangerous marijuana use can be to a pregnant mother and her baby as well. Although marijuana is now legal in many states, it does not mean it is safe to use during pregnancy.

The most common reasons pregnant women use marijuana are to treat morning sickness, lessen aches and pains and help with sleep disturbances. However, the risks to the baby and pregnant mother far outweigh the benefits. There are many safe and effective treatment options for these concerns during pregnancy.

Studies have shown that marijuana use during pregnancy increases the risk of low birth weight, stillbirth, premature birth and the need for admission to the neonatal intensive care unit (ICU). This is true if the marijuana is smoked, eaten in the form of edibles, vaped or applied to the skin in the form of lotions.

There are more than 400 active chemicals in cannabis, many of which cross the placenta to the baby. The fetal brain is growing and developing during pregnancy, and these chemicals can affect the brain in adverse ways. This can lead to learning problems, difficulty focusing and behavioral problems such as increased aggression, beginning in young childhood. One study found that children who were exposed to marijuana in utero performed significantly worse in school and were more than twice as likely to display delinquent behaviors by the age of 14.  These teens also had an increased risk of mental health disorders such as depression and substance abuse.

The chemicals from cannabis can also pass into the breastmilk. These chemicals are stored in fat and are slowly released, so the baby can still be exposed even after the mother stops using marijuana. The evidence of the risks associated with marijuana use during breastfeeding is not as strong. However, the infant brain continues to develop through the age of 3, so there is certainly a risk of adverse consequences. The American Academy of Pediatrics recommends against the use of marijuana by breastfeeding mothers due to possible effects on the infant’s neurobehavioral development.

There are also risks to the pregnant mother resulting from the use of marijuana. It can cause decreased blood pressure and increased heart rate, leading to dizziness and falls. Marijuana use can also increase the risk of anemia, confusion and forgetfulness during pregnancy.

If you are using marijuana and pregnant or planning to become pregnant, please speak with your obstetrician or family practice physician.