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Carbon monoxide screening

Here you'll find resources to support health professionals who screen pregnant women for carbon monoxide (CO).

Carbon monoxide (CO) is especially dangerous during pregnancy because it deprives the baby of oxygen, slows its growth and development, and increases the risk of miscarriage, stillbirth and sudden infant death. It is important that all pregnant women are tested for carbon monoxide.

Resources to support practice

The Smoking in Pregnancy Challenge Group has produced a handout for pregnant women and short guide for professionals on CO screening. These resources can be downloaded here or ordered for free by healthcare teams.

Training video

This short animated video demonstrates how to screen pregnant women for carbon monoxide (CO) and deliver Very Brief Advice (VBA):


Evidence into practice: CO monitoring and data collection throughout pregnancy

This briefing sets out the rationale for carbon monoxide (CO) monitoring and effective data collection throughout pregnancy, and the central role these play in supporting pregnant women to quit smoking. The briefing highlights opportunities for improving data collection, reviews the evidence base for CO monitoring, and includes evidence-based case studies from areas that have improved their data collection and CO monitoring procedures to provide better-quality support to pregnant women who smoke.

Download briefing here

Resources to support CO monitoring after Covid-19

Full implementation of SBLCBv2 Element 1 is now included in the year 4 CNST Scheme. This means that CO monitoring should be carried out at the booking appointment, 36 weeks, and throughout pregnancy. There is no alternative pathway that will be accepted, therefore if trusts are not fully implementing CO monitoring they will fail Safety Action 6.

NHS Resolution - Maternity incentive scheme YEAR 4

The National Centre for Smoking Cessation and Training (NCSCT) has produced specific guidance about how to reintroduce CO monitoring and face-to-face stop smoking support safely.

NCSCT – COVID-19: Face-to-face consultations and CO monitoring

PHE, iPiP and e-LfH have developed a short 10-minute session to support midwives and health visitors in refreshing their skills and ensuring they can undertake a COVID safe intervention.

Reintroduction of CO Testing 10-minute session

Both NHSE and PHE recommend that when resuming CO monitoring in any setting staff should adhere to their monitor manufacturer’s latest guidance on the safe use of products, including the regular cleaning of monitors, replacement of consumables and use of relevant Personal Protection Equipment (PPE) in relation to COVID-19 guidance.

Additional COVID-19 specific guidance now includes:

  • Carry out the test with a minimum 2 metre distance between the SSS adviser and the client, using verbal instructions on how to use the monitor.
  • Ensure the client is not facing the advisor when blowing into the machine.

Ensure the room where CO monitoring is taking place is well-ventilated.

Ask the client to dispose of the mouthpiece into the bin themselves, then wash their hands/use sanitiser.

NOTE: CO monitoring is not classed as an Aerosol Generating Procedure (AGP) and so does not require a FFP3 filtration mask for the adviser undertaking the test.