This factsheet has been written for members of the public by the UK Teratology Information Service (UKTIS). UKTIS is a not-for-profit organisation funded by Public Health England on behalf of UK Health Departments. UKTIS has been providing scientific information to health care providers since 1983 on the effects that medicines, recreational drugs and chemicals may have on the developing baby during pregnancy.

Fentanyl is a very strong painkiller that can be given by mouth in tablet form, by nasal spray, via patches that are applied to the skin, or injected directly into a vein or the spine. Fentanyl is sometimes used recreationally as a drug of abuse.

Very little is known about how fentanyl might affect a baby’s development in the womb and it is therefore not possible to say that it is safe. It is, however, important that pregnant women with severe pain receive appropriate treatment. Any assessment of safety needs to weigh up the risks and benefits to both mother and baby of using fentanyl against those of not using fentanyl. The outcome of this assessment will vary from person to person and will depend on the severity of the mother’s condition.

When deciding whether to use fentanyl during pregnancy it is therefore important to weigh up how necessary it is to your health against any possible risks to you or your baby, some of which might depend on how many weeks pregnant you are.