Not all risk factors for asthma can be prevented. However, environmental factors can be changed.

Current evidence for asthma prevention supports eliminating maternal smoking during pregnancy. There is also concern that if pregnant mothers breathe second-hand smoke, their children may also be at increased risk for asthma.

There is some evidence that reducing exposure to common allergy producing substances during pregnancy and during the first 2 years of life might reduce the risk of developing asthma.

While we do not know for sure that taking acetaminophen during pregnancy increases asthma risk, pregnant women should discuss this and other risk factors with their doctors.