Influence of maternal-infant factors on the development of food allergy in infancy

Background: Perinatal factors, e.g., maternal diet, may impact food allergy development. However, data on socioeconomic status and medical conditions remain limited. Objective: The objective was to identify maternal and infant factors associated with the development of infant food allergy. Methods: We conducted a retrospective cohort study of 228,455 mother-infant dyads in the Kaiser Permanente Southern California system (January 1, 2011 to December 31, 2020). Infants were ages 4‐12 months. Maternal and infant characteristics were compared and adjusted odds ratios (aOR) assessed associations with food allergy development. Results: Infants with food allergy were more likely to have mothers of Asian/Pacific Islander descent (aOR 1.86 [95% confidence interval {CI}, 1.70‐2.03]), with vitamin D deficiency (aOR 1.56 [95% CI, 1.38‐1.75]), atopic dermatitis (aOR 1.40 [95% CI, 1.22‐1.61]), asthma (aOR 1.57 [95% CI, 1.37‐1.81]), food allergy (aOR 2.44 [95% CI, 1.86‐3.21]), or allergic rhinitis (aOR 1.12 [95% CI, 1.03‐1.22]). Median household incomes of $45,000‐$79,999 (aOR 0.82 [95% CI. 0.75‐0.90]) and ≤$45,000 (aOR 0.75 [95% CI, 0.63‐0.90]) compared with ≥$80,000 were inversely associated with infant food allergy. A lower percentage of neighborhood residents with a high school education or higher also correlated with reduced risk (aOR 0.82 [95% CI, 0.73‐0.92]). Additional maternal factors inversely associated with infant food allergy included tobacco use during pregnancy (aOR 0.64 [95% CI, 0.49‐0.85]) and preterm labor (aOR 0.74 [95% CI, 0.64‐0.85]). Conclusion: Analysis of findings from this large retrospective cohort study suggests that both hereditary and environmental maternal and infant factors contribute to the development of food allergy within the first year of life. Early risk identification may support targeted strategies to reduce the prevalence of infant food allergies.