Abstract
Objectives: Prenatal exposures may add to the worldwide increase in asthma prevalence. We estimated the association between maternal work and the asthma prevalence among 7 year offspring.
Methods: Analysis included 45.658 children from the Danish National Birth Cohort and their mothers. Job title (DISCO codes) was classified by exposure agents: High molecular weight (HMW), low molecular weight/irritant (LMW), mixed exposures, farmers, unclassifiable exposures, students and reference (office workers). Children's asthma was defined as ever asthma and/or wheeze in the last 12 months. Atopy was defined as atopic dermatitis ever.
Results: The overall asthma prevalence was 16.1%. The highest asthma prevalence was among children, whose mothers were exposed to LMW/irritant agents during pregnancy (18.6%). Adj. logistic regression analysis showed an association between mother's occupational exposure to LMW/irritants and asthma in the child (OR 1.11 (95% CI 1.01-1.23)). The same tendency was seen for HMW (OR 1.12 (0.85-1.47)). Adjusted models included: Mothers age, BMI, atopy, smoking, use of medication, pets, SGA and gender. Stratifying for atopic status in the children did not change the results: OR 1.21 (0.75-1.96), OR 1.08 (0.77-1.50) for atopic and non-atopic children respectively in the HMW group, and OR 1.13 (0.94-1.35) and 1.13 (1.00-1.27) in the LMW/irritants group. No significant associations to asthma were seen in the other exposure groups.
Conclusion: The results indicate an association between maternal occupational work exposures and the risk of asthma in the child at age 7 years.
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