Carbon monoxide (CO), a colourless, odourless and poisonous gas, is a waste product of cigarette smoking. CO monitoring is an immediate and non-invasive method of determining smoking status (National Institute for Health and Care Excellence (NICE), 2010). CO monitoring has been found to be useful in identifying smokers for referral to specialist smoking cessation services, and it is suggested to be more objective than the use of questionnaires in determining levels of smoking in pregnant women (King and Edwards, 2009), who may feel guilty or ashamed and therefore under-report their smoking habits to midwives.
The measurement of CO level is referred to as a biomarker (King and Edwards, 2009) and is carried out by a breath test. Air is exhaled into the CO breath test monitor and a reading is given after a countdown of 10 seconds.
A chart is provided with details of expected levels, which are colour-coded for ease of use: green indicates normal levels, while red indicates high levels of CO.
CO monitoring is used as a motivation tool for smokers on a quit attempt, to detect smokers and to detect possible exposure to CO in the home environment (O'Gorman, 2011; O'Connell et al, 2014).
Why monitor CO levels in pregnancy?
CO monitoring in pregnancy has been introduced to screen women for smoking, with the intention of maximising referrals to smoking cessation services. Adverse effects of smoking in pregnancy are serious, plentiful and well-researched. Overall, smoking prevalence is continuing to decline in the UK with just over one in 10 women (11.4%) smoking during pregnancy. However, there is a wide regional variation in smoking prevalence with NHS Blackpool reporting highest prevalence at 27.2% and NHS Central London (Westminster) the lowest at 2.1% (Health and Social Care Information Centre, 2015). Women see midwives as a major source of information and advice about health behaviour in pregnancy. A woman's pregnancy may be the only time that she is in regular contact with health professionals; therefore, this is provides a good opportunity for health promotion.
Measuring expired CO is a cost-effective and simple procedure. Identification of smokers should be part of routine practice to highlight the importance of smoking cessation to general health (McNeill et al, 2012).
However, CO monitoring alone is not the most reliable method to determine smoking status. CO disappears quickly from the expired breath; therefore, the reading is not always reliable. Thus, it is still important to ask the woman about her smoking status. CO may have disappeared from the breath of a light smoker (the CO level reduces by 50% 4 hours after a cigarette) and other factors, such as exposure to environmental smoke or lactose intolerance, may cause a high level of CO (NICE, 2010). Exposure to CO in the home from a gas leak or faulty appliance may also cause a high reading. It is important to bear these factors in mind when a high level is found in a non-smoker, and it may be appropriate to investigate further. Urinary cotinine (a metabolite of nicotine) is superior to CO monitoring, but this test is expensive and must to sent to the lab for analysis.
NICE (2010) recommends that midwives explain the health benefits of quitting smoking and advise women to quit, and not just to cut down smoking. All pregnant women should be offered referral to stop smoking services and smoking cessation support (NICE, 2010), in line with the aims identified in the Marmot Review (Marmot, 2010). The review states that all children should have the best start in life; to ensure a healthy standard of living for all; and to create and develop healthy, sustainable communities. If a woman accepts a smoking cessation referral, it is likely she will be offered interventions to help her quit.
A systematic review (Lumley et al, 2009) looked at interventions, such as incentives, nicotine replacement therapy, motivational interviewing and cognitive behaviour for smoking cessation, in over 25 000 pregnant women and found they were successful at helping women to quit by approximately 6%. Later studies have demonstrated the efficacy of financial incentives in successful quit attempts (Mantzari et al, 2012; Tappin et al, 2015). In the most recent study, eligible pregnant women (n=612) were randomly allocated to receive £400 worth of shopping vouchers if they engaged with services and quit smoking, or routine care alone (Tappin et al, 2015). The results were significant—22.5% (control group) vs 8.6% (intervention group) had quit at the follow-up assessment. Exhaled CO was used to confirm quitting. The success of these interventions was found to have a significant consequence of fewer low birth-weight babies and preterm births. Therefore, smoking cessation in pregnancy can improve outcomes for newborn infants. The use of CO monitoring in pregnancy has the potential to increase smoking cessation referrals, thus optimising maternal and infant health.
The use of CO monitoring has not widely been implemented to identify smokers in pregnancy despite recent recommendations by NICE (2010). Furthermore, there has been anecdotal evidence of midwives’ resistance to the introduction of CO monitoring at the booking appointment and of the public's horror at the ‘policing’ of smoking (Clift-Matthews, 2010; McDermott, 2013). It has been speculated that the trusting relationship between the midwife and pregnant woman may be affected by CO monitoring (Clift-Matthews, 2010).
There is evidence that monitoring CO levels in pregnancy is important, but no study has described pregnant women's reactions to being routinely offered CO monitoring. So far, there is no evidence that women oppose being screened for CO in pregnancy.
Aim
The primary outcome of this study was to determine barriers and facilitators to the use of the CO breath test in pregnancy. Findings from this study were described in a previous article (O'Connell and Duaso, 2014). Secondary aims of the study were to describe pregnant women's reaction to the routine use of CO monitoring in the antenatal booking appointment. These will be the focus of this paper.
Method
This phenomenological study was based on midwives’ experiences of using CO monitoring routinely in pregnancy (O'Connell and Duaso, 2014). A descriptive phenomenological approach was deemed an appropriate method for this study since the aim was to investigate midwives’ lived experience of using CO monitoring. It is widely acknowledged that phenomenology aims to describe the lived experience of a phenomenon (Miller and Crabtree, 1992; Rees, 2003; Bassett, 2004; Holloway, 2008; Green and Thorogood, 2009). Robinson (2005) recognises the strength of phenomenology in revealing sensitive and previously unexplored phenomenon.
Nine midwives in Greater and Central London and one midwife from the North of England were given semi-structured interviews using open-ended questions, which were recorded with consent (n=10). The interviews were guided with an interview topic guide to ensure key issues were addressed. Eight of the 10 midwives used CO monitoring routinely at booking. The other two midwives were smoking cessation specialists who used CO monitoring at the point of smoking cessation referral but were not using it in the pregnant women's first booking visit in the clinic. Their midwifery experience ranged from 1–20 years.
Data were analysed using Colaizzi's (1978) method. Mapp (2008) suggests this method of data analysis is suitable in phenomenological studies and can be appropriate for novice to expert researchers. This process involved six steps as described in Table 1. Nvivo 9 software was used to code important statements and link them to emerging themes.
| 1 | Each transcript was read by the researcher |
| 2 | Significant statements from each text in relation to the phenomenon being studied were highlighted and extracted from the transcript |
| 3 | Meanings were generated from the statements |
| 4 | Meanings from the statements were developed into themes |
| 5 | Themes were formulated into main themes and validated by checking against the original transcripts |
| 6 | Results were put into the context of the phenomenon |
Ethical approval
Ethical approval for the study was granted by the Research Ethics committee at King's College London (Ref: PNM/11/12-89).
Results
A number of themes emerged from the data. Barriers and facilitators to the implementation of routine CO testing in pregnancy have been described in a previous publication (O'Connell and Duaso, 2014). This article will first report women's reactions to being offered the CO test, and then women's reactions to the results of the CO test.
Reactions to the CO test
Analysis of the interviews found a general acceptance of routine CO monitoring by pregnant women at the booking appointment. The majority of midwives interviewed described positive reactions from women when offering them CO monitoring. The midwives suggested that CO monitoring has been accepted by pregnant women as part of the normal routine practice at the first antenatal appointment.
‘They're responding really well actually. I haven't seen anybody who declined it … No … nothing. The minute you tell them that it's not just about smoking, but also if you have carbon monoxide in your house, they tend to want to have it.’ (Participant 5)
Participant 5 had a positive experience of CO monitoring. She had not yet detected a smoker who did not self-report. She felt that CO monitoring might be beneficial as she perceived it as a good opportunity to screen vulnerable women in her clinic who are at a higher risk of accidental CO poisoning. Women were keen to be screened, especially when she explained about possible CO poisoning in the home.
Some women experienced communication barriers if an interpreter was not present at the appointment.
Another participant who used the CO test routinely with teenagers gave contrasting feedback, possibly because of the higher prevalence of smoking in this group. Teenagers did not welcome the test; the midwife felt that this was due to how the test was presented to them and their lack of choice:
‘I don't think anybody particularly welcomed it … they weren't happy to have it done, but I think the way it was directed at them was that they didn't have much choice … they would rather not have it done … Yeah, I think any woman that smokes wouldn't want it done otherwise they wouldn't be smoking, they're in denial really.’ (Participant 2)
Non-smokers were surprised that they were being offered the test, but complied when possible accidental CO poisoning was described to them. They had little prior knowledge or information about it. This reinforces the finding that there is a need to educate the public about the introduction of CO monitoring.
Participant 7 said that some women do the test because of interest about the result:
‘They'll do it just to be curious.’ (Participant 7)
Midwives in this study felt anxious about broaching the issue of smoking in pregnancy with women before routine CO monitoring in pregnancy began. However, in practice, women have not expressed difficulties with being offered the CO test, despite the perception by midwives that it is a sensitive issue.
These midwives found offering the test to women became easier with experience and increasing awareness of CO monitoring among pregnant women. It was suggested that pregnant women are generally accepting of any new screening that is introduced in the antenatal period, but there is a perceived lack of public knowledge about CO monitoring and this is a barrier to implementation.
‘I feel that women … didn't understand, had never heard of the fact, that we were offering the test and didn't know anything about it basically, … but once you explained the rationale behind it … the women then engaged then they found it good to know that they had not been exposed to carbon monoxide poisoning. So I usually I say it's worthwhile testing it out … I'm expecting it to be normal with women who say “I don't smoke”.’ (Participant 3)
Reactions to the results
Smokers generally underwent the CO test with no reservations. They were curious to see the result. When women saw their CO levels, most of the midwives described feelings of surprise, relief, alarm, shock, and silence.
One midwife, who had been using CO monitoring since 2000 in her role as a smoking cessation specialist, reported that the most common reactions were surprise and relief:
‘Relieved if it hasn't been too high … yes, surprised and relieved are the two most common reactions from women when they see their results.’ (Participant 4)
In one case, a midwife detected a high CO level in a woman who claimed to be a non-smoker. Her previous medical notes indicated that she did smoke. Was the woman in denial? What if the breath test was inaccurate and the woman had actually quit smoking but was still showing a positive result? What if she had quit but there was a gas leak at home? This woman's reaction of denial highlights the need for midwives to have a non-judgmental and sensitive approach when offering CO monitoring as it would appear that this woman did not want smoking cessation referral and did not want to feel guilty about her smoking in pregnancy. The midwife offered the woman a smoking cessation referral but she declined. None of the other midwives described any experience of ‘catching someone out’ on their smoking status, despite eight out of the 10 midwives using it routinely at booking.
The midwives described women's different reactions to their results from CO monitoring. The impact of the tangible figure as a visual aid for the woman to understand the impact of smoking on the pregnancy was undeniable—some of these women reacted with alarm, shock or surprise at the figure. For some, it may trigger a quit attempt. According to the experience of these midwives, women may be more open to accepting smoking cessation referral when they see their CO level:
‘Some women … were ambivalent. When they've seen their CO reading it has really encouraged them to have a go at quitting.’ (Participant 6)
A few midwives talked about women experiencing the ‘Weight-Watchers effect’, and compared the CO levels to stepping on the scales when trying to lose weight. One midwife had actually used CO monitoring herself to quit smoking and suspected that some women may actually be looking forward to their next reading.
One midwife said that she had experienced a woman who cried when she saw her CO level as she felt guilty about the effect of smoking on her unborn baby. This lady was at a smoking cessation appointment and was struggling to quit:
‘Some people think that it is just nicotine, some people are not even aware that there's carbon monoxide, which is, you know, the poisonous gas … So a lot of time they are quite shocked and … they kind of go silent as well, just taking everything in.’ (Participant 3)
Discussion
As there have not been any previous empirical research studies looking at the lived experience of midwives using the CO test for smoking cessation, findings from this study are significant in providing a comprehensive insight into this new phenomenon. Because this is a new area of research, phenomenology was an effective method in generating an in-depth insight into this new addition to antenatal care and pregnant women's reactions to the CO test as reported by midwives. The midwives who took part in the study were keen to discuss the phenomenon and had significant experience, which led to rich data.
This paper explores women's reactions to CO monitoring according to midwives’ experience of using it routinely since it was introduced, as well as reactions to results of the test. Women appear happy to accept CO screening as part of their routine antenatal care. If women know about the screening at the booking in advance, they will not be surprised to be offered the CO test, and this will make the process smoother. Reactions to the results of the test include alarm, shock, surprise and relief. Women seem to be curious about their result and agree to carry out the test to find out their CO levels. The midwives described that women enjoyed a ‘Weight-Watchers effect’ of the tangible result when on a quit attempt.
There is a possibility that smokers may not be identified by the test if they do not smoke for 48 hours beforehand as CO levels are reduced. This may be a beneficial result of offering the test because, as discussed, stopping smoking for even 48 hours can benefit the fetal oxygen supply. A positive perception of the screening may help to increase the uptake of screening in maternity services thereby increasing referrals for smoking cessation.
Several of the midwives felt that the community they work in may influence their experiences of using CO monitoring and women's attitudes towards it. The midwives worked in an area of high ethnic minority groups with lower smoking rates than the UK as a whole, therefore this finding may not remain true for an area with higher smoking rates since non-smokers are more likely to accept CO testing.
Recent smoking cessation literature has focused on smoking as the biggest cause of health inequalities in high-income countries. Smoking prevalence is higher in lower socioeconomic groups and this remains true for pregnant women (Lumley et al, 2009; Marmot, 2010).
Women in routine and manual occupations had higher levels of smoking before or during pregnancy than professionals (40%) and there is also evidence that mothers who have never worked are the least likely to quit smoking during pregnancy (29%) (McAndrew et al, 2012). Twelve percent of smokers continue to smoke during pregnancy (McAndrews et al, 2012). In poorer parts of Britain, smoking in pregnancy accounts for a third of excess stillbirths and postnatal deaths each year (Office for National Statistics, 2011).
While this study established that pregnant women are open to new pregnancy screening, it also suggested that teenagers did not particularly want to be screened for CO, but they did accept it. Further research is needed to establish whether this is the case. However, in general the benefits of smoking cessation outweigh the risk of damaging the midwife–woman relationship.
Midwives should also be educating women about potential risk of CO poisoning in the home and recommending the use of a CO detector, the results from this study suggest that women seem open to this discussion. These discussions can take place during home visits. Midwives can ask if women have a CO detector installed and advise them to get one.
Adequate support is integral if CO monitoring is to be accepted in routine practice. A smoking cessation specialist midwife is an important link for both pregnant women and midwives who are new to using the test. Contact details should be provided should any issues arise. The midwives interviewed in this study referred to the specialist as the key to success for routine CO monitoring, as they are clinical experts.
Women have the right to decline the test, like any screening, but this should be an informed choice, where they have had the reasons for monitoring clearly explained to them by a midwife. In this study, no midwife had experienced a woman who had declined screening.
Midwives need to offer the test in a sensitive manner and be aware of women's possible reactions to being screened—women can feel guilty about their smoking habits but are addicted. Midwives often fear change and this may be why there is resistance to offering the screening. However, we have adapted to the introduction of many other sensitive screening tools. This study showed that in practice, pregnant women generally have a positive response to the screening. There is a need for further research in this area to investigate a wider range of women's views and experiences of using CO monitoring in pregnancy.
Strengths of the study
This is the first study reporting women's reactions to being offered routine CO monitoring in pregnancy. Knowledge gained from the study could influence further research and has implications for clinical practice and policy. Bracketing was employed to ensure rigour and an accurate description of findings. Colaizzi's method is a standardised method for qualitative data analysis and enhances the transferability of the study.
Limitations
Although member checking is recommended for trustworthiness and credibility, this was not possible owing to time limitations. This study reported women's reactions as reported by midwives. A study investigating women's knowledge and experiences of CO screening is needed. The majority of the participants worked in an area of low prevalence of smoking.
Conclusions
This study found that, overall, women were happy to accept CO monitoring as part of the routine antenatal booking appointment. CO monitoring could save lives through the detection of accidental CO leaks in the home, as well as triggering a referral to smoking cessation. Both midwives and the public need an increased awareness of CO monitoring and its potential benefits.
If CO screening becomes routine in practice as, for example, blood pressure monitoring, the importance of smoking impacts on health will be highlighted. A positive perception of the screening could help to facilitate the implementation of the NICE recommendation for routine screening of all pregnant women.