Study shows that babies born prematurely grow out of their asthma

Large-scale Danish study from the University of Copenhagen shows that premature babies grow out of the asthma which they are likely to develop in early life.

Babies born prematurely are more likely to develop asthma, but they grow out of it. This is the finding of a study conducted by a number of researchers from the University of Copenhagen and which has just been published in the medical journal PLOS ONE.

"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," says Anne Louise de Barros Damgaard, a medical doctor and one of the driving forces behind the study.

The researchers have analysed 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.

"By international standards, this is a very large volume of data and is only possible because of the very detailed databases we have in Denmark. 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," says Theis Lange, an associate professor at the Section of Biostatistics at the Faculty of Health and Medical Sciences and one of the co-authors of the PLOS ONE article.

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," says Theis Lange.