(321) Uptake of prescription smoking cessation pharmacotherapies during pregnancy: a population-based utilisation study across Australia, New Zealand, Norway, and Sweden

Background: Smokers are encouraged to quit during pregnancy due to the increased risk of adverse outcomes. Smoking cessation pharmacotherapies are the most effective strategy available in the general population. Contemporary estimates of the use of smoking cessation pharmacotherapies during pregnancy are lacking.

Objectives: We quantified, across four countries, the utilisation of prescription smoking cessation pharmacotherapies (varenicline, nicotine replacement therapy [NRT] and bupropion) during pregnancy, and the first trimester specifically.

Methods: All pregnancies resulting in birth (2015-2020) in New South Wales (NSW) Australia, New Zealand, Norway, and Sweden were linked to pharmaceutical dispensings and inpatient care records. We conducted a distributed analysis. We defined smoking cessation pharmacotherapy use during pregnancy as days’ supply overlapping the period from date of conception to childbirth. For each country, we calculated prevalence of use among all pregnancies and among pregnancies of women with an indication of smoking during pregnancy. Among pregnant women who used a smoking cessation pharmacotherapy, we quantified the proportion with use in the first trimester of pregnancy.

Results: Among 1.7 million pregnancies across four countries, utilisation of varenicline ranged from 0.02% to 0.14%, prescription NRT ranged from less than 0.01% to 1.86% and bupropion ranged from less than 0.01% to 0.07%. Among 138,033 pregnancies with a smoking indicator, utilisation of varenicline ranged from 0.51% to 1.25%, prescription NRT ranged from 0.10% to 11.39% and bupropion ranged from less than 0.01% to 0.39%. Among women using varenicline, prescription NRT and bupropion in pregnancy, approximately 90%, 60%, and 80% respectively used medicine in the first trimester.

Conclusions: Few women used varenicline or bupropion during pregnancy, whilst NRT was used by a larger proportion. Among pregnancies where smoking cessation pharmacotherapies were used, use in the first trimester of pregnancy was common, indicating the need for evidence on the risk of congenital malformations for these pharmacotherapies.