Cannabis and Pregnancy

Researchers have documented significant risks associated with using cannabis while pregnant. Because of this, the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists recommend that women not use cannabis while they are trying to get pregnant, during pregnancy, and while they are breastfeeding.^1,2 It is extremely important for new mothers using medical cannabis to coordinate care between the doctor recommending their cannabis use and their pediatrician.

There is no research confirming that cannabis use during pregnancy is safe

Cannabis is the most used non-medical drug during pregnancy.² People who are pregnant report using cannabis to relieve pregnancy-related symptoms; to treat nausea and appetite changes,³³ improve mood,⁶ alleviate anxiety or depression,³² and relieve pain.¹⁹ Many use cannabis during pregnancy because they believe that it is safer than prescribed medications and they prefer “natural” remedies.¹  However, there is no research confirming that this is a safe practice.

Using cannabis while pregnant can harm the baby

Fully understanding the effects of cannabis on the developing fetus has been difficult because of research limitations, and because those who use it often use other drugs as well, like alcohol and tobacco.^{2, 14, 20}  Social and environmental factors such as lack of access to healthcare, poor nutrition, and exposure to domestic violence can affect the baby’s growth and development.² These additional factors make it hard to know if negative pre- and post-natal health outcomes are because of cannabis use or other substances.

We do know that tetrahydrocannabinol (THC), the psychoactive or mind-altering ingredient in cannabis, crosses the placenta to the fetus.³¹ There is strong evidence that smoking cannabis while pregnant causes lower birth weight.²³ A recent study found prenatal cannabis exposure to cause smaller head circumference,¹⁸ particularly for those who use throughout their entire pregnancy.⁸ Healthy birth weight and head circumference is important for brain development, good health in childhood, and long-term health into adulthood. Other risks may include a greater risk of stillbirth,²⁸ preterm birth (being born before 37 weeks gestation),¹⁹ and increased admission to the neonatal intensive care unit (NICU).²³

There is some evidence that prenatal cannabis exposure affects learning and memory,²⁶ problem solving skills, motor coordination, and ability to analyze visual objects (e.g., data, art, maps).^30,9,11,5 Additional studies have found that prenatal cannabis exposure is associated with a lower attention span and behavioral problems.^10,13 Also, those who were exposed to cannabis while in the uterus are more likely to use cannabis by age 14, even when other factors that influence drug use are considered.⁷

Secondhand cannabis smoke is harmful to the baby

The THC in secondhand smoke may be passed to infants and children.²⁹ Secondhand cannabis smoke has many of the same cancer-causing chemicals found in tobacco smoke.²¹ Visit our Secondhand Cannabis Smoke page to learn more.

Babies are exposed to cannabis through breastmilk

The impact of cannabis use on breastfeeding infants is still not fully understood. However, there are potential risks of exposure to cannabis through breastmilk. One study found that both THC and CBD were found in breastmilk shortly after the mother used cannabis, whether by smoking or eating it, and could stay in the breastmilk for up to 1-2 days.²² THC stays in the body longer because it combines with fat in the body which is processed more slowly.² High concentrations of THC can accumulate in human breastmilk when cannabis is used regularly.²² THC consumed in breastmilk could affect a baby’s developing brain. One study found decreased motor development at 1 year of age in children exposed to THC through breastmilk in the first month of life.³ The long-term effects of exposure to THC through breastmilk are unknown.

Breastfeeding mothers are encouraged to avoid using cannabis while nursing to prevent potential health risks to their infant.¹

Cannabis use may affect fertility

Studies about the effect of cannabis use on fertility have conflicting results.¹⁷ In women, there is evidence that cannabis use may disrupt the menstrual cycle causing women to not ovulate.¹⁵ Cannabis use may also decrease successful egg retrieval and fertilization through in vitro fertilization (IVF).¹⁶ Similarly, research about the effect of cannabis use on male reproductive health have had mixed results. Some studies show that cannabis use negatively affects a male’s ability to get erect and orgasm and may cause premature or delayed ejaculation.^25,27 Other studies have not confirmed these findings.⁴ Heavy cannabis use can also negatively affect sperm count and function.¹² Cannabis use in both males and females may make it difficult to get pregnant.