MONDAY, March 5 (HealthDay News) -- Babies born just a few weeks early appear to face a greater risk of developing asthma when compared with children born at full term, new research reveals.

The observation applied to infants born between the 34th and 37th week of pregnancy. One-quarter of such "late preterm" babies ended up with an asthma diagnosis by the age of 8 years, despite no prior indications of respiratory illness, the study team found. By contrast, just 15 percent of babies delivered after 37 weeks were found to develop asthma.

"About 10 percent of our babies are born at this [preterm] gestational age, and not much thought is given to their risk of asthma," study co-author Dr. Gretchen Matthews, a pediatrician and neonatologist at the Mayo Clinic Children's Center in Rochester, Minn., explained in a news release from the American Academy of Allergy, Asthma & Immunology (AAAAI).

"What this shows us is that late preterm birth puts children at additional risk for asthma, and so we should initiate diagnosis earlier and maybe take preventive measures earlier," Matthews added. "It wasn't appreciated that this (late preterm) population was different. We can have a huge impact on asthma."

Matthews and her colleagues are to report their findings Monday at the annual meeting of the American Academy of Allergy, Asthma & Immunology, in Orlando, Fla.

The study authors noted that at least 5 million U.S. children are estimated to have asthma, which is now the most common chronic pediatric issue, and prevalence is on the rise.

Given that each year asthma attacks cause U.S. children to miss an estimated 14 million days of school, the Mayo Clinic team said that getting a better handle on factors related to improving early diagnosis could ultimately boost childhood quality of life, while also helping to hold down medical costs. The United States spends about $18 billion a year to treat and manage asthma, according to the AAAAI.

"If we can identify those children that are getting this at an earlier age, we can prevent missed days of school, missed parent workdays, perhaps even prevent some hospitalizations or hospital visits," said Matthews.

While the study uncovered an association between late preterm delivery and asthma in childhood, it did not prove a cause-and-effect.

Data and conclusions of research presented at medical meetings should be viewed as preliminary until published in a peer-reviewed journal.

More information

For more on childhood asthma, visit the U.S. National Library of Medicine.