Premature babies grow out of the asthma which they are likely to develop in early life, according to a recent study from the University of Copenhagen.

Babies born prematurely are more likely to develop asthma, but they grow out of it.

"The study confirms that those born prematurely are more likely to suffer asthmatic symptoms and lung conditions than other children. However, the good news is that they grow out of these conditions. We have looked at premature babies from birth and until the age of about 30, and we can see that the children do better and better. As adults they suffer no more lung conditions than others," Anne Louise de Barros Damgaard, a medical doctor and one of the driving forces behind the study, said in a statement.

For the study, researchers analyzed register data in the form of birth and health details of 1.8 million Danes from the 1980-2009 period, comparing the degree of ill health of persons born before the 37th week of gestation with persons born after that week.

"We have looked at prescriptions for asthma medicine handed in during a specific period to identify probable asthmatics. We have then compared the group of asthmatics with the rest of the population, and the conclusion is clear: Children born prematurely account for a very high proportion of the small children with asthmatic symptoms, but as they grow older, the trend becomes less pronounced," Theis Lange, co-author of the study and an associate professor at the Section of Biostatistics at the Faculty of Health and Medical Sciences, said in a statement.

The discovery that people born prematurely grow out of their asthma is also important from the point of view that more and more premature babies survive not just in Denmark, but worldwide, and because we still have only limited knowledge of their healthiness later in life.

"There are a lot of half stories, myths even, about the health implications of prematurity, and they can be a source of worry for parents of premature babies. It is therefore good to know that as adults premature babies are no more susceptible to lung conditions than other people," Lange said.

The findings are detailed in PLOS ONE.