Advanced maternal age linked to reduced risk of allergic diseases in early childhood

Children born to older mothers appear to have a reduced likelihood of food allergy, wheezing, and house dust mite sensitization in early childhood, according to a study.

Researchers identified singleton live births with data on parental age and allergic outcomes from the Japan Environment and Children’s Study. The primary outcomes were physician-diagnosed food allergy, wheeze, asthma, and eczema at ages 1, 2, and 4 years. House dust mite sensitization at ages 2 and 4 years was also assessed as the secondary outcome.

A total of 34,942 mother-child pairs were included in the analysis. The mean maternal age at study entry was 31 years, and 17,892 mothers (51.2 percent) had a medical allergy history. House dust mite sensitization was assessed in a subset of 1,991 children at age 2 years and 1,840 children at age 4 years.

The prevalence of food allergy at 1 year of age was 6.6 percent (95 percent confidence interval [CI], 6.4–6.9), which decreased as maternal age increased. The odds of food allergy were 21-percent lower for children of mothers aged 35–39 years (OR, 0.79, 95 percent CI, 0.70–0.90) and 41-percent lower for children of mothers aged 40 years and older (OR, 0.59, 95 percent CI, 0.44–0.79) relative to children of mothers aged 25–29 years.

Furthermore, children of parents both aged 35 years or older had 11-percent lower odds of wheezing at age 4 years (OR, 0.89, 95 percent CI, 0.82–0.95).

For house dust mite sensitization, the odds were lower for children of older vs younger mothers (mothers aged 30–34 years: OR, 0.76, 95 percent CI, 0.59–0.98; mothers aged 35–39 years, OR, 0.68, 95 percent CI, 0.50–0.91).