Researchers at the Mayo Clinic in Minnesota, carried out the study as part of the work to uncover what factors increase the risk of a child developing asthma in the first six years of life. Their study, published in the journal Annals of Allergy, Asthma and Immunology, aimed to find out if birth weight was, like genetics and the environment, a factor in a child developing asthma.
The team examined the birth data of almost 4,000 children and noted that only 7% of those with a low birth weight developed asthma, compared with 5% with a normal birth weight. Their conclusion was that birth weight played no role in deciding whether a child developed asthma before the age of six.
Asthma more commonly develops in children than adults and affects around 250 million people around the world. The condition is caused by inflammation in the airways that take air to and from the lungs and is characterised by coughing and wheezing, excess mucus and difficulty in breathing. There is no cure but the symptoms are controlled through medication such as corticosteroids and non-steroid drugs to relieve the inflammation and give pain relief.
There is no known cause for the condition but factors such as genetics, the environment and allergies are all known to play some part in its development. In some adults, the condition is caused by workplace irritants and is known as occupational asthma.