Research has suggested children who sleep on old mattresses during the first year of life are more at risk of developing breathing disorders such as asthma.

A study by The University of Auckland showed that wheezing at ages 3.5 and 7 years was more common in children who slept on a used mattress in the first year of life. Children who were treated with antibiotics or spent time at daycare in the first year of life also showed signs of breathing problems at 7 years old.

The study assessed 871 New Zealand children of European descent at birth and ages 12 months, 3.5 years and 7 years. Any incidents of wheezing or whistling in the chest over the year prior to the assessments were noted, and parents were asked to provide details of lifestyle, including pet ownership, breastfeeding, smoking by members of the household, use of bedding, such as mattresses, quilts and pillows, day care attendance and health and development.

The study found that 24% of children suffered from wheezing at 3.5 years and 18% at 7 years. The main factors associated with children with breathing problems were maternal smoking during pregnancy, being in daycare, antibiotic use, the presence of a dog and sleeping on a used cot mattress in the first year of life.

"Environmental factors are known to have an effect on allergic diseases, such as asthma, particularly in children," says Professor Ed Mitchell of the Faculty of Medical and Health Sciences. "This study has shown that some factors thought to affect children’s breathing, such as use of pillows, do not have a great effect but others, such as maternal smoking, antibiotics, daycare attendance and used mattresses, do. The observation that used cot mattresses are associated with asthma at 7 is particularly intriguing, and may be related to higher levels of house dust mite, endotoxin or other germs in the mattress."

The results of the study are published in the online edition of Clinical and Experimental Allergy.