• Asthma

Respiratory disease taken as a whole is a major global burden contributing significantly to morbidity and mortality at all stages of life. According to WHO estimates, asthma is the most prevalent respiratory condition with over 300 million people affected globally and an additional 100 million diagnoses forecast by 2025. The second most prevalent condition is COPD, with an estimated 210 million suffering globally. Pneumonia and acute lower respiratory illnesses are the leading causes of death in children under 5 years of age, responsible for an estimated 1.4 million deaths annually. It is currently understood that low lung function is a major risk factor linking all these entities, increasing susceptibility to these global health problems.

Lung function is known to track throughout childhood,1 ,2 so to a very real extent the lung function one is born with is a major determinant of future respiratory health.3–5 However, lung function may grow better6 or less well7–9 than anticipated depending on environmental exposures, especially those occurring in early life. Airway branching pattern develops during the first 16–18 weeks of fetal development, with alveolar development beginning later and continuing in early postnatal life. Thus, the respiratory system is vulnerable to adverse environmental exposures in both prenatal and postnatal life. The most compelling data for prenatal exposures influencing lung function at birth10 and beyond11 …