Marijuana and pregnancy

KEY POINTS

  • No amount of marijuana has been proven safe to use during pregnancy.

  • Using marijuana during pregnancy may cause problems for your baby, like premature birth, problems with brain development and stillbirth.

  • It’s not safe to use marijuana to treat morning sickness. Talk to your health care provider about treatments that are safer for your baby.

  • If you use marijuana, don’t breastfeed. You may pass chemicals from marijuana to your baby through breast milk.

  • Talk to your provider if you need help to quit using marijuana or any other street drug.

What is marijuana?

Marijuana (also called pot, weed and cannabis) is a drug that comes from the dried leaves, flowers, stems and seeds of the cannabis plant. Marijuana is the most commonly used street drug during pregnancy. 

Marijuana has more than 500 chemicals, including tetrahydrocannabinol (also called THC). This chemical can affect how your brain works and make it hard to think clearly. THC and other chemicals in marijuana may change your sense of sight, sound and touch.

Using marijuana during pregnancy may cause problems for your baby before and after birth.

What is medical marijuana?

Medical marijuana (also called medicinal marijuana) is sometimes used to treat certain health conditions, like cancer or severe pain. In many states, medical marijuana is legal to use with a recommendation from your health care provider. It can be smoked, vaped or eaten.  The Food and Drug Administration (also called FDA) has not approved marijuana as a safe and effective medicine for any health condition.

In some states, marijuana is legal for personal use that’s not for medical reasons.

Even if it’s legal where you live for either personal or medical use, no amount of marijuana is  safe to use marijuana during pregnancy, even to treat morning sickness. There is also no safe way to use marijuana. If you’re thinking of using marijuana to help with morning sickness, talk to your provider about other treatments that are less harmful to your baby.

Is it harmful to use marijuana before pregnancy?

Yes. Before pregnancy, using marijuana can affect your fertility and make it hard for you to get pregnant. Marijuana can affect:

  • Hormones that your body needs to get pregnant. Hormones are chemicals made by the body.
  • Your menstrual cycle. This is the process of your ovaries releasing an egg every month.
  • A man’s sperm count (the number of sperm he makes). A man’s sperm fertilizes a woman’s egg to begin a pregnancy.

Can using marijuana during pregnancy cause problems for your baby?

Yes. When you use marijuana during pregnancy, THC and other chemicals can pass through the placenta to your baby. The placenta grows in your uterus (womb) and supplies your baby with food and oxygen through the umbilical cord. Chemicals from marijuana also may pass to your baby’s brain.

Researchers are continuing to study the effects of marijuana use during pregnancy.  Women who use marijuana may smoke cigarettes, drink alcohol or use other street drugs, making it hard to know exactly how marijuana affects pregnancy. Some studies suggest that if you use marijuana during pregnancy, your baby may have problems, including:

  • Premature birth. This is birth that happens too early, before 37 weeks of pregnancy. 
  • Fetal growth restriction (also called growth-restricted, small for gestational age and small for date) and low birthweight. Fetal growth restriction is when a baby doesn’t gain the weight she should before birth. Low birthweight is when a baby is born weighing less than 5 pounds, 8 ounces. Your baby also may have short body length or small head size.
  • Anencephaly. This is one of the most severe neural tube defects (also called NTDs). NTDs are birth defects in the neural tube, the part of a developing baby that becomes the brain and spine. Babies with this condition are missing major parts of the brain, skull and scalp. Most do not survive long after birth, usually for just a few hours. Babies exposed to marijuana during the first month of pregnancy are at increased risk of having anencephaly.
  • Anemia. This is when your baby doesn’t have enough healthy red blood cells to carry oxygen throughout the body.
  • Problems with brain development.
  • Stillbirth. This is when a baby dies in the womb after 20 weeks of pregnancy. 

If you use marijuana during pregnancy, your baby can have problems after birth and may need to spend time in the neonatal intensive care unit (also called NICU). A NICU is the nursey in a hospital where sick newborns get care. These problems include:

  • Withdrawal symptoms, like tremors (shakes), seizures, vomiting, slow weight gain or long periods of crying after birth. These symptoms usually go away within the first two weeks after birth.
  • Problems with sleeping.
  • Problems with behavior, memory, learning, problem-solving, depression and paying  attention.

How does using marijuana affect breastfeeding?

If you breastfeed your baby and smoke marijuana, you may pass THC and other chemicals to your baby through the breast milk. Than can make your baby more likely to have problems with brain development. Marijuana also may affect the amount and quality of breast milk you make. The American Academy of Pediatrics recommends that breastfeeding moms stay away from marijuana to help keep breast milk safe and healthy.

Can using marijuana harm your general health?

Yes. The more marijuana you use, the more likely you are to have problems, including:

  • Very fast heart rate
  • Lung problems, including  bronchitis and chronic cough (like a smoker’s cough)
  • Trouble paying attention or thinking clearly
  • Memory problems
  • Trouble sleeping
  • Clumsiness and poor coordination and balance

How can you get help to quit using marijuana?

Talk to your health care provider. He can help you get treatment to quit. Or contact:

More Information

Last reviewed: September 2020