Patterns of Smoking Behaviour in Low-Income Pregnant Women: a Cohort Study of Differential Effects on Infant Birth Weight

Introduction:
This article presents the results of a cohort study examining the impact of smoking patterns during pregnancy on infant birth weight (BW) among low-income women. The study also considers the influence of second-hand smoke (ShS) and other smoking and socio-demographic variables.

Key Points:

* The study included 652 women who were smokers at the time of pregnancy and attended public ante-natal clinics.
* Smoking patterns were categorized as sustained quitters, continued smokers, initial smokers who had quit, and any other quit attempt during pregnancy.
* The study found that total quitting showed a median increase of 288 g in BW, compared to partial quitting (147 g).
* household ShS had a specific negative influence on pre-term but not term BW.
* Longer gestational age at birth, female gender, and multiple pregnancies were significantly associated with higher BW.
* Smoking status at the first ante-natal visit, number of cigarettes smoked at the first and second visits, and pattern of smoking throughout pregnancy were strongly associated with BW.
* additional home smokers, but not partner smoking, were significantly associated with reduced BW.

Main Message:
The study suggests that quitting or partially quitting smoking during pregnancy has a positive impact on infant BW, and that others in the household not smoking is also important. The findings highlight the need for appropriate interventions and supports for women who continue to smoke during pregnancy, particularly for low-income women for whom quitting may not be an attainable goal. The study also emphasizes the importance of addressing ShS exposure in the household environment to improve birth outcomes.

hayes, Catherine, Morgan Kearney, helen O’Carroll, Lina Zgaga, Michael Geary, and Cecily Kelleher. “Patterns of Smoking Behaviour in Low-Income Pregnant Women: a Cohort Study of Differential Effects on Infant Birth Weight.” International Journal of Environmental Research and Public health 13, no. 11 (October 29, 2016): 1060. https://doi.org/10.3390/ijerph13111060.