Emerging data shows that the increasing frequency of early-onset ‘noncommunicable’ illnesses, such as pediatric atopy, is linked to modern environmental changes, the consequences of which appear to begin in utero or even before conception. The study discusses how recent papers have advanced the knowledge of the impact of in-utero exposures on the proclivity to immunological dysregulation, with a specific emphasis on the changing epidemiology of pediatric allergies. New data shows that nonheritable variables, such as periconceptional environment, are primarily responsible for inter-individual differences in immune function development. Maternal diet during pregnancy is one of the most important factors. New research lends support to a well-balanced maternal diet rich in immunomodulatory substances, prebiotics, and probiotics, all of which help various areas of fetal development, including immunological function. Furthermore, diminishing maternal biodiversity, maternal stress, and environmental pollution exposure all interact to have a negative impact on the growing immune system.

The fetal phase looks to be a key era. Further research into gene-environment interaction pathways is required before making suggestions for early-life preventative measures to minimize the rising global burden of allergy illness and other ‘noncommunicable’ diseases.