If you smoke around your baby, he could develop more colds and respiratory infections than if you didn't smoke around him. Cigarette smoke itself doesn't cause colds -- viruses cause colds -- but breathing secondhand smoke can increase your baby's risk of catching a cold by irritating and damaging his respiratory tract. Secondhand smoke might also affect your baby's immune system, decreasing it's effectiveness.
Upper Respiratory Infections
Cold viruses are everywhere, especially in the winter months. Your baby won't necessarily catch every cold virus that comes his way. However, because his immune system might not function as well as that of a baby not exposed to smoke, and because smoke exposure damages his respiratory tract, he's more likely to catch the cold viruses he runs into. Most children suffer from between six and nine colds per year, Vanderbilt Children's Hospital pediatrician Dr. Christopher Harris reports in "Nashville Medical News." For children exposed to secondhand smoke, the rate of colds per year rises to 12 to 18.
Lower Respiratory Infections
Infants exposed to cigarette smoke have impaired lung function and decreased lung efficiency, which makes them more likely to succumb to more serious respiratory infections if they catch a cold. Secondhand smoke also impairs lung growth. When upper respiratory infections spread to the lower lobes of the lung, they can cause potentially more serious infections, such as bronchitis or pneumonia. Environmental tobacco smoke causes as many as 150,000 to 300,000 lower respiratory tract infections each year in children under age 18 months, resulting in around 15,000 hospitalizations, the American Academy of Otolaryngology quotes from an Environmental Protection Agency study.
Other Respiratory Complications
Not all runny noses come from colds. If your baby seems to have a constant cold, he might actually have allergies, which also occur more commonly in children of smokers who exposed them to passive smoke. Smoking around your baby nearly triples his risk of developing allergic rhinitis, or a runny nose caused by allergies, according to an October 2006 study published in Environmental Health Perspectives. Being around secondhand smoke also increases your baby's risk of death from sudden infant death syndrome. Chronic cough, sore throat and postnasal drip also affect babies surrounded by secondhand smoke more often.
Decreasing the Risks
Between 50 and 67 percent of American children live with at least one smoker, according to the American Academy of Otolaryngology. Just stepping outside and away from your baby when you smoke greatly decreases his risk of developing colds or other respiratory infection. Babies whose mothers smoked around them had a 50 percent higher risk of hospitalization in the first year of life from a respiratory infection, with 7.8 percent of infants hospitalized at least once for respiratory infections, in an Australian study published in the March 2003 issue of the American Journal of Public Health. However, if a smoking mother didn't smoke around her baby, she decreased the extra risk of illness requiring hospitalization by 70 percent.