As part of your care during pregnancy (antenatal care), you will be offered a carbon monoxide breath test to help you and your baby be healthy.
Carbon monoxide is a colourless, odourless and tasteless poisonous gas which can kill people. Cigarette smoke is the most common source of this gas, but it can also come from exhaust fumes, faulty gas appliances, coal or wood fires and oil burning appliances.
The breath test measures the amount of CO in your blood. You hold your breath and then blow into a mouthpiece.
It only takes a few minutes with immediate results which tell you if you have been exposed to unsafe levels of CO.
The most likely reason for a high number on your CO test is exposure to cigarette smoke, either from smoking or if someone in your home smokes.

Reducing your exposure to cigarette smoke is the most important thing you can do for your and your baby’s health.
You can:
• quit smoking yourself
• avoid being around other people who are smoking
• ask others not to smoke in your home, in the car or in front of you.
The good news is that once you stop, the carbon monoxide will clear from your bloodstream and your baby’s. This will allow oxygen to flow to support their growth and development
Your midwife can discuss options to help you quit smoking, including referring you to on-site or local stop smoking services, and the use of nicotine replacement therapy during your pregnancy to help you quit. To find out more about the free supports available to you and those you live with who smoke, call the Quitline on 1800 201 203 or visit