Modifiable prenatal environmental factors for the prevention of childhood asthma

The prevalence of asthma in children is increasing worldwide, yet risk factors for the development of asthma is unclear. Evidence to date indicates that environmental factors are the main reason of the recent increase in the prevalence of asthma. For example, exposure to air pollution and diet as well as microbial alterations are reported as environmental factors. In addition, we should focus on the critical period of the exposure, especially pregnancy period as an important period for human development. Therefore, environmental exposure during pregnancy to tobacco smoke or air pollutants, maternal stress, obesity, and vitamin D may contribute to the development of childhood asthma. Herein, modifiable prenatal exposure, its mechanisms associated with childhood asthma and multiple intervention controlling risk factors needed during pregnancy in order to achieve primary prevention of asthma has been described.