The association of parental age at delivery with childhood allergic disease and the modified effect of breastfeeding.

Background: Childhood allergic diseases are a global concern; quite limited studies have examined the impacts of parental age at delivery. This study aimed to explore the association between separate and combined parental age at delivery and childhood allergic diseases and whether adequate breastfeeding could modify this association.

Methods: This cross-sectional study sampled 15,976 children from Shanghai, China. The International Study of Asthma and Allergies in Childhood questionnaire was adopted to evaluate allergic diseases. Multivariate logistic regression models were used to examine the association of parental age and exclusive breastfeeding with allergic diseases.

Results: The prevalence of allergic rhinitis, asthma, food allergy, drug allergy, urticaria, and eczema was 21.2%, 14.2%, 8.7%, 3.9%, 15.6%, and 35.5%, respectively. Either of parental age at delivery ≥25 years could increase the risk of allergic diseases in most cases, where paternal age showed a stronger effect. The risk was further elevated when parental age were both ≥25 years (OR ranged from 1.266 to 1.541, all p < .05 except for drug allergy). Breastfeeding >6 months was inversely associated with all types of allergic diseases and involved in attenuating the risk caused by parental age ≥25 years. These findings were generally validated by sensitivity examination as well as stratified analyses.

Conclusions: Parental age at delivery ≥25 years was a risk factor for most childhood allergic diseases. Breastfeeding >6 months applied to modifying the risk chalked up to parental age. These findings are significant given the rising age of parents and increasing prevalence of childhood allergic diseases.