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Carbon monoxide poisoning and pregnancy-what you need to know

When you’re pregnant there can be so many things people tell you to be worried about. While some of these concerns may turn out to be old wives tales or false alarms, there are a number which aren’t and one of these is the danger of carbon monoxide poisoning. Carbon monoxide is a very dangerous gas which you cannot see, smell, taste or feel.

1. Carbon monoxide poisoning and pregnancy

If you are pregnant and experience carbon monoxide poisoning, it means that you are putting your baby at risk of miscarriage, death or stillbirth. If you are pregnant, this means that you are even more vulnerable to carbon monoxide poisoning. Other groups who are vulnerable to it in particular, are young children and babies, and also people with breathing problems or heart problems.

2. High risk groups include:

  • pregnant women

  • babies

  • young children

  • those with breathing problems

  • those with heart problems

carbon monoxide poisoning pregnancy

3. Pets and carbon monoxide poisoning and pregnancy

In your house, it may surprise you to know that actually it will be your pets who showed the first signs of poisoning. This is because they are also especially vulnerable to the effects of this gas. So if your pet becomes suddenly ill, or worse still actually dies, without it being related to some previously known condition, then you will want to investigate immediately the possibility of carbon monoxide poisoning.

4. So let’s look at some of the common signs of carbon monoxide poisoning:

  • unexplained headaches
  • feeling dizzy when standing up
  • unexplained chest pains
  • muscular weakness
  • feeling lethargic
  • feeling dizzy
  • feeling sick
  • being sick
  • feeling confused
  • feeling tired
  • having difficulty breathing
  • shortness of breath
  • pains in your stomach

5. When the symptoms become even worse:

1) People like you can even experience memory loss through this poisoning
2) It is also possible to start experiencing coordination problems
3) This poisoning can also lead to serious confusion.

6. What happens when there are high levels of carbon monoxide?

  • a person could lose consciousness
  • in fact if the levels of the gas are very high death can even occur within minutes
  • chest pain could occur which could be caused by either a heart attack or angina
  • vertical could occur
  • personality changes brought on by intoxication
  • impaired mental state
  • seizures
  • breathlessness
  • tachycardia

7. How is carbon monoxide produced?

Carbon monoxide is produced when certain fuels such as coal, wood, gas or oil, do not burn entirely. If a fire is burning in an enclosed space, for example in a room where oxygen is being used up slowly, then it will be replaced by carbon dioxide. This means that the fuel is then unable to burn entirely and starts to release carbon monoxide.

What happens to you when you breathe in carbon monoxide?

When you breathe in carbon will it it will enter your bloodstream and then mix with haemoglobin, and will form carboxyhaemoglobin. Once this happens, your blood is no longer able to carry out the function of carrying oxygen throughout your system. Of course this lack of oxygen will cause your body’s cells, as well as tissues, to die.

8. Some tell-tale signs to be aware of:

  1. If people you either live with, or work with, become unwell with the same or very similar symptoms to you, then you need to consider carbon monoxide poisoning.
  2. If the symptoms you are experiencing go away, when you go to a different environment, such as visiting people going to work or going on holiday.
  3. Also if your symptoms become exaggerated during different seasons, especially if during the winter when you need to use your heating more, you notice more dramatic symptoms.
  4. Be aware if there are yellow flames instead of blue flames coming out of your gas appliances.
  5. If you observe such marks on walls which are close to your stoves, fires or boilers.
  6. Also be aware of those type of city black marks on the front of your gas fire.

9. Here’s a checklist of some of the main causes of carbon and poisoning:

  • smoking around you
  • damaged heating appliances heating
  • appliances with faults
  • if you use your cooking appliances to heat the room
  • if you have blocked chimneys
  • or if there are blocked flues
  • incorrect installation of heating appliances
  • bad or incorrect operation of heating appliances
  • rooms in your house which are not properly ventilated
  • using your outdoor heater in doors
  • using your barbecue in doors
  • not servicing your heating appliances

10. What to do if you suspect carbon monoxide poisoning

If you, or anyone you live with or work with, shows symptoms that having outlined in this article, make sure the person gets fresh air straight away. Open all windows in your house or workplace. Move immediately away from the suspected source of the gas. Stop using all appliances until the culprit has been discovered. Then go straight to the doctor and ask your doctor to test for carbon poisoning.

When your doctor tests for poisoning, there will be two factors that will influence the amount of CO in your bloodstream. These are:

1. The length of time of exposure
2. How much CO has been in the air supply

Of course like any other health issue, the reaction of the person in question, be it yourself or another person, will also depend on their general state of health. Additionally the persons recovery will depend on the combination of these factors.

Obviously you need to stop using whatever appliance you believe may have been the cause of the poisoning. This appliance should be checked straight away by the correctly qualified person.

Oxygen therapy treatment:

When you or another person has been exposed to an especially high level of CO, it will be necessary to get oxygen therapy treatment. This will be delivered in a hospital, and the person will need to wear a tight fitting mask and will breathing air which contains approximately 21% oxygen. Because this is such concentrated oxygen, your body will be able to replace the carboxyhaemoglobin quite quickly.

Sadly, the statistics show that somewhere between 10% and 15% of people who have suffered from very severe CO poisoning, do go on to develop complications in the long term. These can, unfortunately, include damage to either the heart or the brain.

Image credit for featured image:

Carbon Monoxide concentrations in spring.

Midwife sonographer facilitated

Consultant Led, Centre of Medical Excellence 


All articles on the blog and website are intended as information only. Please do not consider any of the information provided here as a substitute for medical advice. At all times seek medical advice directly with your own doctor and medical team.


This website was formerly Merrion Fetal Health. The clinic has undergone a rebrand and is now known as Merrion Ultrasound.