Gestational age and the risk of allergic diseases: a systematic review and meta-analysis.

BACKGROUND

The perinatal period has been postulated to be a window of opportunities in preventing atopic disorders. Accumulating studies suggested that an association exists between gestational age (GA) and allergic diseases.

METHODS

The meta-analysis of observational studies was conducted through a search of relevant literature until 31 December 2023 from PubMed, Embase, and Web of Science databases. Subgroup analyses and sensitivity analyses were performed to test the robustness and consistency of the observed associations.

RESULTS

Thirty observational studies comprising 5,410,969 participants were included in the meta-analysis. The pooled estimates (odds ratio [OR]) of atopic dermatitis (AD) risk for early preterm, preterm and post-term birth were 0.75 (95% confidence interval [CI]: 0.68-0.82), 0.86 (95% CI: 0.81-0.93), 1.08 (95% CI: 1.03-1.14), respectively. Additionally, early preterm birth was suggestively associated with reduced risk of allergic rhinitis (AR) (OR: 0.84, 95% CI: 0.73-0.97).

CONCLUSION

Our study demonstrated that early preterm and preterm births were associated with a reduced risk of AD, while post-term birth was linked to an increased risk, with early preterm birth also suggestively associated with a reduced risk of AR.

IMPACT: This large-scale meta-analysis demonstrates that early preterm and preterm births are associated with a significantly reduced risk of atopic dermatitis (AD), while post-term birth is linked to an increased risk. Early preterm birth is also suggestively associated with a lower risk of allergic rhinitis (AR), highlighting the nuanced role of gestational age in the development of allergic diseases. These findings underscore the importance of the perinatal period as a critical window for allergy risk stratification and early prevention strategies in pediatric populations.