Epidemiology of Smoking During Pregnancy by Women’s Country of Birth and Indigenous Status in Victoria, Australia: A Comparative Trend Analysis

Despite its harmful effects, smoking during pregnancy among Australian overseas-born women remains under-researched. This study examined smoking during pregnancy among women who gave birth in Victoria from 2011 to 2020, categorized by birthplace and Indigenous status. We analyzed data from the Victorian Perinatal Data Collection, encompassing 777,068 women who gave birth in Victoria, Australia, between 2011 and 2020. Women were classified into four groups based on birthplace and Indigenous status. Smoking during pregnancy was assessed through self-reported data based on the number of cigarettes smoked daily. Overall, smoking proportion during the first 20 weeks of pregnancy was 9.2% (95% CI: 9.1–9.3), with a 30.7% reduction from 11.7% (95% CI: 11.4–11.9) in 2011 to 8.1% (95% CI: 7.9–8.2) in 2020. The overall proportion of smoking at high intensity (smoking >10 cigarettes/day) at ≥20 weeks of pregnancy declined by 41.3%, from 19.1% (95% CI: 17.9–20.4) in 2011 to 11.2% (95% CI: 10.2–12.3) in 2020. Indigenous Australian women comprised the largest proportion of smokers during pregnancy at 41.2%. Women aged ≤20 years compared to >35 years, single women compared to married, women living in the most disadvantaged areas compared to the least disadvantaged areas, and grand multigravida women compared to primigravida had higher rates of smoking during pregnancy. Despite the overall declining trend in smoking during pregnancy, smoking rates in certain groups remain high. Targeted smoking cessation interventions, in addition to strengthened national and state-level smoking control strategies, are needed to further reduce smoking rates during pregnancy.