Researchers can't say why, but it appears that when you're born may determine your risk for asthma.
A new study based on the medical records of more than 95 thousand children from Vanderbilt University finds that infants born four months before the peak of the cold and flu season, which is generally in the fall, have a nearly 30 percent risk for developing asthma. Researchers found this risk to be similar to or greater than other well-established risk factors for asthma.
They say it's logical to think that triggers in the environment may be to blame. and propose two non-mutually exclusive possible reasons for the link: One, that there is a genetic susceptibility common to both bronchiolitis and the development of asthma; and two, that an environmental exposure such as a winter viral infection causes asthma.