Determining a strategy to reduce smoking in pregnancy

Background Further efforts, informed by current data, are needed to reduce smoking during pregnancy. Aims To describe trends in smoking during pregnancy and identify regions most likely to benefit from targeted smoking cessation interventions, in New South Wales (NSW), Australia. Materials and Methods All women who gave birth in NSW between 1994 and 2016 were included. Smoking status was identified from the Perinatal Data Collection. For births between 2012 and 2016, women were grouped into Local Health District (LHD) of residence, and smoking rates calculated. The impacts of a hypothetical smoking cessation intervention in four LHDs with (i) high smoking rates and (ii) high numbers of smokers, were compared. Results The overall smoking rate during pregnancy decreased from 14.5% in 1994 to 8.3% in 2016. The decrease was lowest among women living in the most socioeconomically disadvantaged areas (41%) and highest among those living in the most advantaged areas (83%). Between 2012 and 2016, over half the women who smoked during pregnancy lived in one of four LHDs. Only 1% of women reporting smoking during pregnancy resided in the LHD with the highest smoking rate (34.7%). A simulated intervention targeting only four regions showed greater effect on the statewide smoking rate when targeting LHDs with high numbers of smokers rather than high smoking rates. Conclusions Despite decreases in rates of smoking during pregnancy, there was evidence of geographic clustering of smokers. The greatest reduction in overall smoking may come from interventions targeting the four LHDs with the highest number of smokers.