Benefits of not smoking during pregnancy for Australian Aboriginal and Torres Strait Islander women and their babies: a retrospective cohort study using linked data

Abstract

ObjectivesTo provide evidence for targeted smoking cessation policy, the aim of this study was to compare pregnancy outcomes of Aboriginal mothers who reported not smoking during pregnancy with Aboriginal mothers who reported smoking during pregnancy.DesignPopulation based retrospective cohort study using linked data.SettingNew South Wales, the most populous Australian state.Population18 154 singleton babies born to 13 477 Aboriginal mothers between 2010 and 2014 were identified from routinely collected New South Wales datasets. Aboriginality was determined from birth records and from four linked datasets through an Enhanced Reporting of Aboriginality algorithm.Exposure Not smoking at any time during pregnancy.Main outcome measuresUnadjusted and adjusted relative risks (aRR) and 95% CIs from modified Poisson regression were used to examine associations between not smoking during pregnancy and maternal and perinatal outcomes including severe morbidity, inter-hospital transfer, perinatal death, preterm birth and small-for-gestational age. Population attributable fractions (PAFs) were calculated using adjusted relative risks.ResultsCompared with babies born to mothers who smoked during pregnancy, babies born to non-smoking mothers had a lower risk of all adverse perinatal outcomes including perinatal death (aRR=0.58, 95% CI 0.44 to 0.76), preterm birth (aRR=0.58, 95% CI 0.53 to 0.64) and small-for-gestational age (aRR=0.35, 95% CI 0.32 to 0.39). PAFs (%) were 27% for perinatal death, 26% for preterm birth and 48% for small-for-gestational-age. Compared with women who smoked during pregnancy (n=8919), those who did not smoke (n=9235) had a lower risk of being transferred to another hospital (aRR=0.76, 95% CI 0.66 to 0.89).ConclusionsBabies born to women who did not smoke during pregnancy had a lower risk of adverse perinatal outcomes. Rates of adverse outcomes among Aboriginal non-smokers were similar to those among the general population. These results quantify the proportion of adverse perinatal outcomes due to smoking and highlight why effective smoking cessation programme are urgently required for this population.

Active and Passive Maternal Smoking During Pregnancy and Birth Outcomes: A Study From a Developing Country

“…As shown in previous research, active and passive maternal smoking during pregnancy increases the risk of having a child with low birth weight [27,34] and significantly increases other negative pregnancy outcomes, such as preterm birth [17,21], respiratory distress [1], antepartum and intrapartum stillbirth [5], perinatal death [24], long-term morbidity in offspring [32], and sudden unexpected infant death [3].…”

Association of Prenatal Exposure to Maternal Drinking and Smoking With the Risk of Stillbirth

“…2 A strong association between maternal smoking during pregnancy and stillbirth has been reported. [3][4][5] Although associations have been found for maternal drinking during pregnancy and abortion, being small for gestational age, and stillbirth, [6][7][8] the association with stillbirth may be limited to binge drinking. 9 Previous studies 9,10 that assessed the association between stillbirth and maternal drinking or smoking have often been retrospective and have inadequately classified quantity, frequency, and timing of exposures.…”

Determining a strategy to reduce smoking in pregnancy

“…With both programs having an important element of a reduction in pregnant women smoking, renewed attention on smoking cessation in pregnancy is timely. A recent study of 18 154 singleton babies born to Aboriginal mothers residing in NSW found that 20% of stillbirths and 26% of preterm births were attributable to smoking in this population, as well as 30% of neonatal deaths and 48% of small for gestational age births 21 . Among this population 51% of women reported smoking; however, in order to comply with our ethics requirements for this study, we were unable to separately enumerate smoking rates for Aboriginal mothers.…”

“…These concerns were echoed in interviews with young pregnant women in Western Australia who said that being surrounded by smokers made it difficult to stop, and had worries about being excluded from their social sphere if they quit 24 . Although data were not available from this study for Aboriginal people, it is known that smoking rates among Aboriginal mothers are higher than the general population 21 . Effective interventions, especially for the subgroups of women identified as being more likely to smoke during pregnancy, are required.…”

“…24 Although data were not available from this study for Aboriginal people, it is known that smoking rates among Aboriginal mothers are higher than the general population. 21 Effective interventions, especially for the subgroups of women identified as being more likely to smoke during pregnancy, are required. As these women may be less likely to engage with antenatal care providers, 25 and out-ofpocket cost (such as those that may be incurred for nicotine replacement therapy) is likely to be a major barrier to some mothers, 26 these groups may not be an appropriate target for trialling large scale interventions.…”