Most drugs that a mother takes will cross the placenta and affect her foetus, or will be present in her breast milk.
Using heroin while pregnant can increase the chances of problems in pregnancy such as miscarriage, or going into labour early, which can mean that babies are born below birth weight.
Heroin is often "cut" with other substances that can also cause problems during pregnancy and affect the developing foetus.
Read more about the effects of taking heroin during pregnancy or breastfeeding.
Check with your doctor or other health professional if you are using or planning to use heroin or any other drugs during pregnancy or while breastfeeding.
For more information, please click on the Australian Drug Foundation's DrugInfo Clearinghouse web site link below.
Last Reviewed: 04 February 2011