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Medications, Cannabis, & Other Drugs

Since almost all medications reach the baby through the placenta or in breast milk, you may be worried about how safe it is to use medications. While few studies have been done on the safety of medications in pregnancy, we know that while some increase the chance of birth defects or problems and are not safe, others have been used for a long time and are considered safe.

To ensure the prescription, over-the counter and herbal supplements you are taking or thinking of taking are safe and absolutely necessary:
don’t make decisions based on lists you find on the internet.
be open with your health care provider.
review the benefits, any risks, and if there are safer alternatives or non-drug treatments worth considering.

If you have a health condition such as asthma, nausea and vomiting in pregnancy, depression, high blood pressure, epilepsy or are receiving treatment with methadone or buprenorphine:

  • you might need to continue taking medication to stay healthy during your pregnancy.
  • your health care provider will discuss the benefits and risks and prescribe the safest option for you.
  • don’t change or stop your medication without first talking with your health care provider. Sometimes there is more risk for you and
  • your baby by stopping a medicine. Also, some medicines can cause withdrawal symptoms and need to be reduced slowly.

Your pharmacist can also give you information about the safety of medication during pregnancy. Use this information to start a conversation with your health care provider about what medicines would work best for you.

Herbal Products
Natural health products may include vitamins and minerals, herbal remedies, homeopathic medicine, traditional Chinese and East Indian medicine, probiotics as well as amino and fatty acids. Products that are considered natural can still contain ingredients that could be harmful to your baby. Few have been studied for how well they work and for their safety. Always check with your health care provider first and proceed with caution.

If your health care provider suggests a herbal product to prevent or treat symptoms:
use approved products. Look for the eight-digit Natural Product Number (NPN) or Homeopathic Medicine Number (DIN-HM) on the label. It identifies products that are licensed and approved for use in Canada.
read the label information so you know what the ingredients are, what it is used for, the dosage, and any known risks or side effects.

What about essential oils?
Essential oils are concentrated oils taken from plants. They are used in aromatherapy, a complementary therapy. The oils are breathed in or applied to the skin to promote health and a sense of wellbeing. They are sometimes used in labour to reduce anxiety and the need for pain medication. Substances in the oil are thought to stimulate brain cells or have an effect on hormones or enzymes in the blood.

Opinions differ on using essential oils in pregnancy. They appear to not cause harm, but their safety in pregnant women has not been well studied as:

  • there isn’t information on many oils because they have never been tested.
  • some oils are known to be toxic, cause cancer or irritate and should be avoided.
  • a person’s medical history may make using an oil more risky for them but not for someone else (e.g. skin irritation, allergies).
  • Using essential oils is a personal decision. It is always safest to talk to your health care provider first.


Cannabis can be smoked, inhaled as vapour or ingested in food, drinks or as an extract. There are hundreds of chemical substances in the cannabis plant. Tetrahydrocannabinol (THC) is the chemical that makes a person feel “high”.

Using cannabis while pregnant or breastfeeding can be harmful. While there is lots we don’t know, research has shown that cannabis can increase the risk of a baby being born too early and having a low birth weight. Cannabis can also affect the developing brain and increase a baby’s risk of future problems with learning, behaviour and mental health. These effects can last into the teenage years and beyond. Some people who use cannabis a lot have severe nausea, vomiting and abdominal pain that is relieved with hot bathing. Medical care is sometimes required.

Because there is no known safe level of cannabis use for pregnant women, it is safest not to use cannabis during your pregnancy.
Explore other treatments with your health care provider that don’t carry the risks that cannabis does if you:

  • suffer from nausea and vomiting of pregnancy.
  • struggle with anxiety.
  • use cannabis for medical reasons.
  • Do not allow anyone to smoke or vape in your home or around your baby.
  • If you are having trouble stopping or reducing your cannabis use, help is available. Talk to your health care provider or contact Fourcast.

Myth: Cannabis is natural so it must be safe.

Not all natural substances are safe. Many plants contain poisons and toxins (e.g. poison ivy). Cannabis is a drug. And like other drugs, it has side effects that can be harmful.

Risks of Cannabis on Fertility, Pregnancy, Breastfeeding and Parenting
(Best Start Resource Centre)

Other Drugs
If other drugs are part of your life, being pregnant can be a powerful motivator for change. The desire to have a healthy baby can be so strong you may be ready to take some or all of these important first steps.
Admit you use drugs. This can be hard to do. You may worry that you will be judged if you tell anyone. You may also have feelings of shame, guilt, and loneliness or doubt that you can stop. These worries and feelings are all normal.
Tell a loved one or friend you trust and/or Fourcast (page 60 in the directory) that you need help. It is important to have support as you recover.
Talk to your health care provider so he/she can:

  • advise you on the safest way to quit or decrease.
  • provide the right care and treatments.
  • link you to services that will support you, your baby and your family.
  • Consider counselling to help you with your feelings and to make healthy choices. Counselling can be especially helpful if you have experienced partner violence, depression or trauma.

It is important to continue receiving care after your baby arrives to prevent a set- back. Parenting a new baby can bring a different set of stresses. To help decrease stress levels in both mothers and babies, skin-to-skin for comfort and breastfeeding are encouraged.

It’s never too late to stop or decrease using drugs in pregnancy. The sooner you can start the better. Know that there are supports to help you on this journey. You owe it to yourself!

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