USA: Prenatal Antibiotic Exposure and Childhood Asthma

An increasing number of antibiotics courses, early timing, and broad-spectrum prenatal antibiotic exposure were associated with increased risk for childhood asthma, according to a recent study published in the journal Clinical Infectious Diseases.

In the population-based cohort study, which involved 84,212 mother-child pairs enrolled in Tennessee's Medicaid program from 1995 to 2003, researchers from Vanderbilt University and Louisiana State University looked at prenatal antibiotic exposure and the development of asthma in the children by the age of 6 to fully understand the relationship between the two, and to investigate whether any association was modified by a familial disposition to asthma. A total of 54,141 children (64%) were exposed to antibiotics prenatally.

Compared with never-exposed children, exposure to prenatal antibiotics increased the odds of childhood asthma by 23% after adjusting for covariates (adjusted odds ratio [aOR], 1.23; 95% confidence interval [CI], 1.18 to 1.28). Prenatal antibiotic exposure was also associated dose-dependently with increased odds of childhood asthma (aOR for an interquartile increase of 2 courses [0, 2], 1.26; 95% CI, 1.20 to 1.33).

Among children exposed to at least one course in utero, the effect of timing at the first course was moderated by total maternal courses. Among women receiving a single antibiotic course, the timing of exposure had no effect on childhood asthma risk. Among women receiving more than one course, early exposure of the first course was associated with greater childhood asthma risk. Compared with the use of narrow-spectrum antibiotics only, broad-spectrum-only antibiotic exposure was associated with increased odds of asthma (aOR: 1.14; 95% CI, 1.05 to 1.24).

Although children with asthmatic mothers were more likely to be prenatally exposed to antibiotics, the number of courses and timing of the first course was not significantly associated with childhood asthma development. The significant dose-dependent relationship between the number of prenatal antibiotic courses and childhood asthma persisted only in children whose mothers did not have asthma, as did the significant timing effect of first prenatal antibiotic exposure on childhood asthma.

For more details, click on the link: https://doi.org/10.1093/cid/ciaa085