So say Norwegian researchers including the University of Oslo's Geir Haland, MD, in The New England Journal of Medicine.
Haland and colleagues studied the lung function of healthy, full-term newborns shortly after birth and followed up 10 years later.
They found that children with reduced lung function at birth were more likely to have had asthma by the time they were 10 years old.
To measure lung function, the 802 babies tested briefly wore tiny face masks as the researchers tracked their breathing patterns.
Such tests aren't new, but they're not routinely performed at birth.
None of the babies had severe breathing problems. But some had better lung function than others.
Ten years later, the researchers followed up on 616 of the children.
The 10-year-olds took several breathing tests -- including one done as they ran on a treadmill. They also took allergy, blood, and urine tests. In addition, their parents reported whether the children had ever had asthma.
The finding: Kids with reduced lung function at birth were more likely to have ever had asthma by the time they were 10.
The results held when the researchers took other factors into account, such as whether the kids' parents had asthma and if their moms had smoked during pregnancypregnancy.
"These results suggest that alterations of airway function associated with later asthma may be present and detectable a few days after birth," write the researchers.
However, they aren't recommending lung function tests to screen newborns for asthma risk.
Why not? Lung function can vary in the first few days after birth, explain Haland and colleagues.
"Thus, our data would not support the use of such measures as screening tests for the risk of subsequent asthma," they write.