OBJECTIVE: To assess (i) the effectiveness of a mass media campaign communicating the potential harms associated with consuming even small amounts of alcohol in pregnancy and (ii) changes in females' intentions to abstain during pregnancy after campaign exposure.

METHODS: Independent samples of ∼400 Western Australian adults (18-45 years) were recruited at two time points (before and after the 'One Drink' campaign) to complete online surveys. Attitudinal and behavioural intention outcomes were assessed at both time points. Descriptive analyses and generalised linear models were used to assess outcomes.

RESULTS: Three-quarters (76%) of the post-campaign sample members reported awareness of the campaign. In the descriptive analyses there were significant improvements in three of the seven attitudinal items. The regression models yielded significant increases in agreement that pregnant women should not drink alcohol (assessed among females and males) and intentions to abstain during pregnancy (assessed among females only).

CONCLUSIONS: The results indicate favourable understanding and behavioural intention effects from exposure to a campaign promoting alcohol abstinence during pregnancy.

IMPLICATIONS FOR PUBLIC HEALTH: This study demonstrates that investment in campaigns warning about alcohol use in pregnancy is likely to be a worthwhile approach to reduce the burden of alcohol-related harms to individuals and society.