A recent study reports that babies who are born in autumn are more likely to develop asthma than babies born at any other time of year. According to the study, newborns with birthdates four months before the peak of cold and flu season have a 30% greater risk of developing childhood asthma than other babies.

Researchers at Vanderbilt University examined the records of 95,000 infants and their mothers in Tennessee. They found that all babies who had a clinically significant lung infection called bronchiolitis at any time during infancy were at increased risk of asthma, but autumn babies had the greatest risk.

While it was already known that babies born during the fall in the Northern Hemisphere have a greater risk of developing asthma, this study is the first to connect that increase with the timing of peak viral activity in the winter months.

The increase in asthma risk may be related to a common respiratory virus called the respiratory syncytial virus or RSV that is responsible for many of the cases of cold-like symptoms experienced by adults and children each winter. Most children are infected with RSV early in life, with infections occurring most often between the ages of 3 and 6 months. The virus usually clears up without serious complications. However, in some cases it can lead to bronchiolitis which, as this study demonstrates, is associated with greater asthma risk.

The researchers propose that while genetic risk factors probably predispose some children to developing asthma, RSV infection during the winter may be the environmental trigger that activates those asthma risk genes. If so, this suggests that preventing RSV infection in newborns could prevent them from developing asthma.

So should you call your child’s pediatrician and ask for an RSV vaccine shot? Unfortunately, no such vaccine yet exits, but several pharmaceutical companies have RSV vaccines in development. There is a drug called Synagis (palivizumab) that provides passive immunity against RSV but it must be administered monthly at a cost of around $2000 per dose and it is usually reserved for babies at high risk of RSV complications (such as those born premature).

For now, parents of newborns born in autumn should take precautions to try to prevent spreading RSV infection to their baby. A simple way to help prevent RSV infection is to wash your hands often, especially before touching your baby. Other tips for RSV prevention include insisting that others wash their hands before touching your baby, keeping people with colds or fevers away from your baby, avoiding contact with other young children, and making sure your baby is not exposed to tobacco smoke.

For more information on asthma, see the Healia Health Guide on Asthma or ask the online community at the Healia Health Community for Asthma. If you have asthma and your symptoms worsen during the wintertime, you may be able to better control your asthma symptoms. See the Healia Health Guide on Uncontrolled Asthma for more details.

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