Antibiotics in pregnancy tied to asthma in children: study

Similarly, these children were also 18 percent more likely to have been given a prescription for an asthma medication than children whose mothers did not take antibiotics when they were pregnant.

His team also looked at a smaller group of 411 children who were at higher risk for asthma because their mothers had the condition. They found that these children were twice as likely as their peers to develop asthma too if their mothers took antibiotics during the third trimester of pregnancy.

Others said that it was possible that something besides the antibiotics was responsible, such as the illness the drugs were prescribed for.

This study, it doesn't tell us whether it's the antibiotic use or whether it's the infection. That's one thing we can't decipher, said Anita Kozryskyj, a professor at the University of Alberta who also studies the antibiotics-asthma link but wasn't involved in the new study.

The results don't suggest that women should avoid antibiotics since some infections can be quite dangerous to a fetus, she said, adding that Bisgaard's study suggests that the development of asthma might start before birth, something researchers hadn't studied very closely.