A review carried out by a team of medical experts from Nanchang University, China, has highlighted prenatal and childhood risk factors such as parents smoking, birth weight, preterm birth, mode of delivery, childhood respiratory infections and childhood asthma for developing COPD later in life. These risk factors are in addition to the immediate risk factors such as smoking, air pollution etc. 

The researchers said that it is important to talk about early risk factors because exposure to these often occurs decades before abnormal lung function. They also dedicated sections of their review to other individual risk factors such as low birth weight, maternal nutrition, vitamin D deficiency along with socioeconomic stress factors.