Dr Sophie Orton is a Senior Research Fellow in the School of Medicine at the University of Nottingham and an SSA Academic Fellow. Her research focuses on reducing the harms associated with smoking in pregnancy, including smoking cessation, nicotine replacement therapy (NRT), e-cigarette use and postpartum smoking relapse prevention. Her current SSA fellowship explores the use of NRT for smoking reduction among pregnant women who are unable to achieve complete smoking cessation.

Abstract

Does nicotine replacement therapy reduce smoking when pregnant people cannot quit abruptly? A within-person analysis

Aims: Despite high motivation, many pregnant people who smoke cannot quit abruptly. Previously, among those who continued smoking, we found an inverse relationship between daily nicotine replacement therapy intake and cigarettes per day. This study investigated this association in a larger sample of pregnant people who smoke enrolled in a cessation trial, focusing on whether greater daily nicotine replacement therapy use is linked with lower cigarette consumption.

Methods: Data were ecological momentary assessments from the SNAP2 smoking cessation trial. Eligible participants were pregnant, smoked daily, and willing to set a quit date and attempt quitting with nicotine replacement therapy (N=410). Daily reports of cigarettes per day and nicotine replacement therapy intake were collected via the NicUse application for 28 days post quit date. Mixed-effects models examined within and between-person associations, adjusting for time and baseline heaviness of smoking.

Results: Most participants (79%) smoked after quit dates, averaging about three cigarettes per day; 88% of these also used nicotine replacement therapy (mean 27mg/day). Within-persons, cigarettes per day were lower on days with greater nicotine replacement therapy use; for light smokers, each 10mg was associated with −0.21 cigarettes per day (95% CI −0.31, −0.11, p<.001). Heaviness of smoking index moderated this association (−0.51 for moderate-heavy). No between-person association was observed.

Conclusions: Most participants smoked and used nicotine replacement therapy. Within individuals, daily nicotine replacement therapy intake was inversely related to cigarettes per day, suggesting that nicotine replacement therapy was used as a substitute for cigarettes. For pregnant women unable to quit smoking abruptly, using nicotine replacement therapy could reduce prenatal exposure to tobacco smoke. Findings support considering harm reduction approaches within cessation support, particularly where complete abstinence is not immediately achievable during pregnancy despite high motivation to quit.