Fetal and infant origins of asthma

Liesbeth Duijts

doi:10.1007/s10654-012-9657-y

Abstract

Previous studies have suggested that asthma, like other common diseases, has at least part of its origin early in life. Low birth weight has been shown to be associated with increased risks of asthma, chronic obstructive airway disease, and impaired lung function in adults, and increased risks of respiratory symptoms in early childhood. The developmental plasticity hypothesis suggests that the associations between low birth weight and diseases in later life are explained by adaptation mechanisms in fetal life and infancy in response to various adverse exposures. Various pathways leading from adverse fetal and infant exposures to growth adaptations and respiratory health outcomes have been studied, including fetal and early infant growth patterns, maternal smoking and diet, children’s diet, respiratory tract infections and acetaminophen use, and genetic susceptibility. Still, the specific adverse exposures in fetal and early postnatal life leading to respiratory disease in adult life are not yet fully understood. Current studies suggest that both environmental and genetic factors in various periods of life, and their epigenetic mechanisms may underlie the complex associations of low birth weight with respiratory disease in later life. New well-designed epidemiological studies are needed to identify the specific underlying mechanisms. This review is focused on specific adverse fetal and infant growth patterns and exposures, genetic susceptibility, possible respiratory adaptations and perspectives for new studies.

Highlights

Previous studies have suggested that asthma, like other common diseases, has at least part of its origin early in life
Long term follow up studies in different populations have shown that impaired respiratory health or lung function in early childhood is associated with asthma and other respiratory diseases in later life [42–48]
The developmental plasticity hypothesis suggests that the associations between low birth weight and diseases in later life are explained by early adaptation mechanisms in response to various adverse exposures in fetal life and early childhood [64]

Summary

Developmental origins of childhood asthma

Low birth weight has been shown to be associated with increased risks of asthma, chronic obstructive airway disease, and impaired lung function in adults [57–61]. The developmental plasticity hypothesis suggests that the associations between low birth weight and diseases in later life are explained by early adaptation mechanisms in response to various adverse exposures in fetal life and early childhood [64]. Other mechanisms underlying the associations of low birth weight with asthma and respiratory diseases in childhood and adulthood might include an innate or T helper 2 skewed immune system, increased allergen sensitization, inflammation and bronchial hyperreactivity [72–75]. These different underlying mechanisms may lead to various phenotypes of asthma with onset at different ages

Fetal growth characteristics

Maternal smoking and diet

Exposures in infancy

Genetic susceptibility

Findings

Conclusion