Globally, guideline-recommended antenatal care for smoking cessation is not routinely delivered by antenatal care providers. Implementation strategies have been shown to improve the delivery of clinical practices across a variety of clinical services but there is an absence of evidence in applying such strategies to support improvements to antenatal care for smoking cessation in pregnancy. This study aims to determine the effectiveness and cost effectiveness of implementation strategies in increasing the routine provision of recommended antenatal care for smoking cessation in public maternity services.

A non-randomised stepped-wedge cluster-controlled trial will be conducted in maternity services across three health sectors in New South Wales, Australia. Implementation strategies including guidelines and procedures, reminders and prompts, leadership support, champions, training and monitoring and feedback will be delivered sequentially to each sector over 4 months. Primary outcome measures will be the proportion of: (1) pregnant women who report receiving a carbon monoxide breath test; (2) smokers or recent quitters who report receiving quit/relapse advice; and (3) smokers who report offer of help to quit smoking (Quitline referral or nicotine replacement therapy). Outcomes will be measured via cross-sectional telephone surveys with a random sample of women who attend antenatal appointments each week. Economic analyses will be undertaken to assess the cost effectiveness of the implementation intervention. Process measures including acceptability, adoption, fidelity and reach will be reported.

Ethics approval was obtained through the Hunter New England Human Research Ethics Committee (16/11/16/4.07; 16/10/19/5.15) and the Aboriginal Health and Medical Research Council (1236/16). Trial findings will be disseminated to health policy-makers and health services to inform best practice processes for effective guideline implementation. Findings will also be disseminated at scientific conferences and in peer-reviewed journals.

Australian New Zealand Clinical Trials Registry—ACTRN12622001010785.