Asthma more common among premature babies
A new Swedish study claims that premature babies are more likely to need medication for asthma than those born at term. This also applies to children born as little as one week early.
Earlier this year another Swedish study was published and showed an increased risk of asthma for children born very early, between the 23rd and 27th week of pregnancy. However, for children born after the 27th week no correlation was found. But a recent survey of more than a million Swedish children aged between six and 19 years, turns these results around.
It turns out that the risk of medicating children for asthma steadily increases in proportion to the declining number of weeks in the womb. The researchers see an increased risk for children born during the 37th or 38th week of pregnancy, compared with children born full term.
“Every week the child is in the womb appears to be important for the reduction of the risk that the child will get asthma later in life. This means that one should avoid pre-term delivery, as far as possible, "said Hartmut Vogt, a medical specialist at the Children's and Youth Hospital in Linköping. He is also a doctoral student at the Department of Clinical and Experimental Medicine, (IKE) at, Linköping University, and one of those who worked on the study.
He also says that the team was surprised that even children born at 37-38 weeks are at a higher risk than children born full-term.
“But it is also reasonable to believe that the gradual development of the lungs during foetal life is significant, even during the final weeks of a pregnancy, "he says.
Scientists have retrieved the basis for the study from the official health records of the National Board of Health and Welfare, and they investigated more than 1.1 million children between the ages of six and 19. They also identified the number of children in 2006 that at least on one occasion were prescribed asthma medication (inhaled steroids), which was 4.9 % of boys and 3.8 % of girls. This has then been compared to the gestational period.
The likelihood that the child required asthma medication was higher among all categories for pregnancies below 39 weeks and this increased in line with the reduced number of weeks in the womb. This applies to both girls and boys and also taking into account a number of other factors, for example, if the birth occurred by Caesarean section or if the mother has smoked during pregnancy.
The survey also shows that the risk decreases with increasing age of the child.
The results of the study, conducted by Hartmut Vogt, Linköping University, Karolina Lindström and Anders Hjern, Karolinska Institute and Lenny Bråbäck, Umeå University, was published in the journal Pediatrics, also attracted international attention by the news agency Reuters Life.
Text: Monica Westman Svenselius
Last updated: 2012-12-10