Studies have suggested that antibiotic use in pregnancy and childhood may increase the risk for asthma, but a large Swedish study has found strong evidence that there is no such connection.
Researchers followed 493,785 children, including 180,894 siblings, from the start of their mothers' pregnancies to school age. More than 20 percent had been exposed to antibiotics in utero and 62 percent during childhood. Overall, 6 percent had asthma.
The study, published in The BMJ, initially found an apparent link between antibiotic use and asthma, but the association disappeared when researchers looked at siblings. They found no difference in asthma development between siblings who had taken antibiotics and those who had not, suggesting that other factors are at work.
Asthma, they write, may be misdiagnosed as a respiratory disease and then treated with antibiotics. When asthma later appears, the antibiotics are incorrectly identified as the cause. Researchers also found no association between asthma and antibiotics given for urinary tract or skin infections.
The study did not test other possible reasons for the development of asthma. "We haven't looked into other factors," said the lead author, Dr. Anne K. Ortqvist of the Karolinska Institute in Stockholm. "But we think that previous results may have been biased by shared genetic and environmental factors within families."
ActiveStyle on 01/26/2015