Occupational Exposure During Pregnancy and the Risk of Atopic Dermatitis in the Offspring

Background: The prevalence of atopic dermatitis (AD) has increased considerably in the last decades. The major predisposing factor for AD is an inherited epithelial barrier defect due to loss-of-function in the filaggrin gene. Environmental factors are also hypothesised to cause AD. The aim of the present study was to analyse whether maternal occupational exposure to allergens or irritants during pregnancy is associated with AD in the offspring. Methods: A total of 41,724 mother-child pairs from The Danish National Birth Cohort were categorized according to maternal occupational exposure assessed by combining occupation during pregnancy and a job exposure matrix. AD in the offspring was defined by a combination of parentally reported AD and eczema in locations typical for AD. Results: AD was identified in 14.9% and 11.7% of the children by age 18 months and 7 years, respectively. By age 18 months, maternal mixed low- and high molecular weight agents exposure (health care workers) during pregnancy was positively associated with AD (OR 1.07 (95% CI: 0.98-1.16)). Maternal exposure to low molecular weight agents showed a borderline significantly decreased risk of AD (OR 0.88 (0.78-1.00)). By age 7, none of the maternal exposure groups were associated with a changed risk of AD in the offspring. Conclusions: Our results do not suggest maternal exposure during pregnancy to be a significant risk factor for AD in the offspring. Exposure of pregnant women employed in the healthcare sector to e.g. antibiotics, latex and cleaning agents might pose a risk factor for AD in their offspring