WEDNESDAY, Sept. 28, 2011 (HealthDay News) -- Just like extremely premature babies, infants born between 33 and 34 weeks' gestation can have impaired lung function at ages 8 to 9, but in these moderately premature children, lung function may improve by the time they are teenagers, research shows.
"There has been a lot of research demonstrating the negative effects that extreme premature birth can have on the lung function of children, but limited data on the lung function of moderately preterm-born children, especially as they grow older," the study's lead author, Sarah Kotecha from Cardiff University, in the United Kingdom, said in a news release from the European Lung Foundation.
Babies born earlier than 40 weeks of gestation may have immature, or not fully developed, lungs. This can result in severe breathing difficulties such as respiratory distress syndrome, the study authors noted in the news release.
In conducting the study, the researchers followed children born just six to seven weeks early and examined them at the age of 8 to 9 years, then again at the age of 14 to 17 years using a spirometry test, which measures how well the lungs function. The lung function of children born prematurely was compared to children who were born at full term.
The investigators found that babies born around 33 or 34 weeks' gestation had significantly lower lung function at the age of 8 to 9 years than children who were born at full term. When the children were re-tested as teenagers, however, the lung function of the moderately preterm kids improved.
"Ours is the first study to highlight these deficits of lung function in children born moderately prematurely and the improvements as children grow older," noted Kotecha. "The number of babies who survive premature birth has increased over the past 30 years and it is encouraging to see that these children improve as they grow older."
The study findings were slated for presentation Tuesday at the European Respiratory Society Annual Congress in Amsterdam. Research presented at medical meetings should be viewed as preliminary until published in a peer-reviewed journal.
The American Pregnancy Association provides more information on premature birth complications.