Medicines and pregnancy overview

Many medicines can be taken safely when you are pregnant but it is important to check with your doctor, midwife or pharmacist first. Some medicines may cause harm but not treating some conditions during pregnancy can be just as risky or more risky to you and your baby.

The decision about whether to use medicines during pregnancy depends on your individual circumstances. Your doctor or midwife will look at whether the risk of taking medicine is higher than the risk of not treating your illness, and if you or your baby would face worse problems without treatment. 

The effects of your medicine on you and your baby may depend on many factors, such as:

• the safety categories of medicines
• how much medicine you take (the dose)
• the stage of pregnancy you take the medicine
• other health conditions you have
• other medicines you take.

Many women think that herbal and homeopathic remedies and aromatherapy (sometimes called natural medicines) are safe, but this is not necessarily the case. Not all "natural" remedies are safe in pregnancy. Examples of supplements that should be avoided in pregnancy, include vitamin A, vitamin D, black cohosh, dong quai, butterbur, cat’s claw, fenugreek, flaxseed and flaxseed oil, goldenseal and liquorice root. Also, since there is lack of regulation of the quality or contents of herbal and homeopathic products, they may be contaminated with heavy metals, toxic plants, bacteria and pharmaceutical impurities. 

Tell your doctor, midwife or pharmacist if you're using herbal, homeopathic or aromatherapy remedies. If you do decide to use these therapies, you should always check with your doctor, midwife or pharmacist. You should tell your practitioner that you're pregnant before discussing any treatment.  

Not all pregnancies are planned. Some women will already be taking medicines when they find out they’re pregnant. If you took medicines before you learned you were pregnant, talk with your GP or midwife about any changes you may need to make. Don't stop taking any prescribed medication. Talk to your doctor first. 

It can be hard to know if a medicine is safe for your baby. Most medicines are not well studied in pregnant women, because researchers worry about how the medicines might affect the baby. But some medicines have been taken for so long by so many women that doctors have a good idea of how safe they are. Talk to your doctor or midwife before you take any medicines.

What are the safety categories of medicines during pregnancy?

When your doctor or midwife discusses your options about medicine use in pregnancy, they may look up the safety category for medicines in pregnancy. There is a safety category system for prescribing medicines in pregnancy which have been developed by medical and scientific experts based on levels of risk. This information is to help make decisions when prescribing medicines to pregnant women and takes into account the known effects of medicines on the baby, including birth defects, effects around the time of birth, and problems that may occur in later life.

Categorisation systems are only a guide and should not be the sole basis of decision making.

Can I use information I find online?

Take care when looking at online sources about medicine safety in pregnancy. You can use this information to start a conversation with your healthcare professional. Many websites post lists of medicines that are “safe” to take during pregnancy. However, for many medicines, there is not enough scientific evidence to be sure of their safety during pregnancy.

You also need to consider how these might interact with other medicines or supplements you are taking, which is why it is advised to talk to your healthcare professional to get the complete picture.