Asthma best fought in the womb
Every week of pregnancy is important to avoid the fetus developing asthma later in childhood. Even full-term babies born in weeks 37-38 have an increased risk, as shown by data from over one million Swedish children born between 1987 and 2000.
Hartmut Vogt, a pediatrician at the University Hospital and PhD student in pediatrics at Linköping University, has compared data from the Swedish medical birth registers with statistics of dispensed asthma medication from the Swedish Prescribed Drug Register. This is an indirect measure of the presence of the disease, which has been found to correlate quite well with the actual overall picture.
“We knew there was a connection between very premature birth and lung disease in young children. But according to one of our studies, even those who were born in weeks 37 and 38, had a ten percent higher risk of asthma than those born at 39-41 weeks. This has not been shown before”, says Hartmut Vogt, who now presents the results in his doctoral thesis.
The development of the lungs begins shortly after conception and lasts until two or three years of age. Premature infants are born with fewer lung sacs and limited lung function, which poses a risk for both asthma and bronchitis.
“Life in the mother's womb plays a major role in the child's health in the future, but time after birth is also important”, says Hartmut Vogt.
Another study looked at the consumption of asthma medication in foreign-born persons compared with Swedish-born persons. This indicated that the age of immigration to Sweden played a major role. Children adopted by Swedish parents in the first year of life were twice as likely to develop asthma when compared to children adopted after the age of four. Environmental factors seem to have a great significance in determining the risk of developing asthma as a child and young adult.
Today there is no further evidence-based research into how asthma in children can be prevented, apart from that parents should not smoke either during pregnancy or later.
Another, important public health message from the thesis is that vaccination against pertussis in early childhood is safe and does not increase the risk of developing asthma as a teenager.
Asthma is a chronic inflammatory disorder of the airways. The symptoms are recurrent breathing problems with shortness of breath, chest tightness and coughing. In young children, the first sign is often a wheezing sound.
Photo: Very premature babies often suffer from asthma (photo: Peter Modin). Hartmut Vogt now shows that even children born in weeks 37 to 38 have an increased risk of developing the asthma.
Thesis: Early life factors and the long-term development of asthma by Hartmut Vogt. Linköping University medical dissertations No. 1325, 2012. The defense took place on 6 December.
Contact: Hartmut Vogt 010-1030000 (county council switchboard), hartmut.vogt @ liu.se
Last updated: 2012-12-10