Comparison of saliva cotinine and exhaled carbon monoxide concentrations when smoking and after being offered dual nicotine replacement therapy in pregnancy

Abstract

Background and Aims: Although English Stop Smoking Services routinely offer dual nicotine replacement therapy (NRT) to help pregnant women to quit smoking, little is known about how nicotine and tobacco smoke exposures following this compare with that from smoking. We compared, in pregnant women when smoking and after being offered dual NRT, saliva cotinine and exhaled carbon monoxide (CO) concentrations and numbers of daily cigarettes smoked. Design and Setting: Secondary analysis of data from three sequential, observational, mixed-methods cohort studies conducted as part of the Nicotine Replacement Effectiveness and Delivery in Pregnancy programme. Participants were recruited on-line or in Nottingham University Hospitals (UK) antenatal clinics between June 2019 and September 2020.Participants: Forty pregnant women, who agreed to try stopping smoking.Intervention: Participants were offered dual NRT, agreed a smoking quit date and received an intervention to improve adherence to NRT. Measurements: Saliva cotinine and exhaled CO concentrations and reported number of cigarettes smoked per day.Findings: There were no differences in saliva cotinine concentrations at baseline and day 7 post quit date [n = 20, mean difference = −32.31 ng/ml, 95% confidence interval (CI) = −68.11 to 3.5 ng/ml; P = 0.074, Bayes factor = 0.04]. There were reductions in the reported number of cigarettes smoked per day (n = 26, mean difference = −7 cigarettes, 95% CI = −8.35 to −5.42 cigarettes, P < 0.001) and concurrently in exhaled CO concentrations (n = 17, ratio of geometric means = 0.30 p.p.m., 95% CI = 0.17-0.52 p.p.m.; P < 0.001). Conclusion:Pregnant women who smoke and are offered dual nicotine replacement therapy (NRT) appear to show no change in their exposure to cotinine compared with

The Relationship Between Reported Daily Nicotine Dose from NRT and Daily Cigarette Consumption in Pregnant Women Who Smoke in an Observational Cohort Study

“…However, if smoking were under-reported in our study, this would have diluted the relationship between NRT dose and cigarette consumption, but our bespoke NicUse app reports of cigarettes smoked per day have shown a strong relationship with exhaled CO concentrations. 33 , 36 Reports of NRT use have been found to be more complete and accurate than retrospective questionnaire reports, 44 so we can have confidence that our self-report measures reflect smoking and NRT use. A further potential limitation is the lack of ethnic diversity within our sample, who were all White British, however the sociodemographic profile of our sample was similar to other pregnancy cohorts, which have high proportions of women who were White British with generally lower education.…”

“… 32 Those offered “dual” NRT for quitting (ie, two types of NRT together, at high dose), and reported some cigarette use rather than managing to stop smoking completely, smoked fewer daily cigarettes and exhaled less CO than when smoking, but salivary cotinine concentrations remained unchanged. 33 …”

“…From limited available evidence, 32 , 33 it seems likely that in pregnancy, using NRT drives smoking reduction. However, we are not aware of any studies in pregnancy that have collected detailed data on use of NRT or that have investigated the association between NRT use and smoking using within-person methodology, and so no attempt has been made to address this important gap.…”

Development and Content Validation of a Questionnaire for Measuring Beliefs About Using Nicotine Replacement Therapy for Smoking Cessation in Pregnancy

“…However, like typical support users, participants were under no obligation to accept NRT and were recruited in a similar way to the current opt-out system offered in England for pregnancy smoking cessation. From our recruitment rates and demographic information, 28 we believe our sample to be typical of research participants in pregnancy cessation studies.…”

“…As part of an intervention optimization study, the methods of which are detailed elsewhere, 28 item piloting was carried out with pregnant women who agreed to undergo a smoking quit attempt with NRT and to receive a prototype adherence intervention called “Baby, Me & NRT.” Ethical permission was granted by Nottingham 1 Research Ethics Committee (reference 19/EM/0193). Underpinned by the Necessities and Concerns Framework, 14 and also the Perceptions and Practicalities Approach, 26 Theoretical Domains Framework 29 and Behavior Change Wheel, 30 “Baby, Me & NRT” is a blended (in-person and digital) behavioral intervention designed to effect positive changes in the barriers and facilitators of pregnancy NRT adherence identified through research described in Phase 1.…”