Introduction:
Bushfire smoke exposure is linked to adverse pregnancy and neonatal outcomes; however, the specific impact of bushfire smoke exposure on pregnancies complicated by asthma is not well characterised.
Aim:
Explore the impact of bushfire smoke exposure and subsequent poor air quality on maternal and neonatal outcomes amongst pregnant women with a pre-existing diagnosis of asthma.
Materials and Methods:
A retrospective cohort study analysed data from 22,166 pregnant women that gave birth in the Illawarra Shoalhaven region between January 2017 and December 2020. Asthmatic women were identified by the presence of an ICD-10-AM code for asthma during their hospital admission for birth. Women were considered to have been exposed to bushfire smoke if they experienced at least 4 weeks of their pregnancy between 25th of October 2019 to the 4th of February 2020.
Results:
The prevalence of asthma in the total population studied was 8.31%. Outcomes of asthmatic pregnancies were poorer than non-asthmatic pregnancies. Bushfire smoke exposure did not alter odds of maternal and neonatal outcomes; increased odds of PPH (OR 1.603; 95% CI 1.42-1.81); and decreased odds of gestational hypertension (OR 0.615; 95% CI 0.49-0.77), gestational diabetes (OR 0.703; 95% CI 0.63-0.79) and pre-term birth (OR 0.813; 95% CI 0.67-0.98).
Conclusions:
This study emphasizes effects of asthma on pregnancy outcomes; however, impact of bushfire smoke exposure on asthmatic pregnancies remains unclear. Further research is needed to delineate the true effect of bushfire smoke exposure on asthmatic pregnancies and characterise the effect in the context of varying levels of exposure.