Turi KN, Gebretsadik T, Ding T, et al. - Researchers here examined how timing, dose, and spectrum of prenatal antibiotic exposure correlate with the risk of childhood asthma. In this population-based cohort study, they examined 84,214 mother-child dyads for the relationship of prenatal antibiotic exposure and childhood asthma using multivariable logistic regression models. Receipt of antibiotics was reported in 64% of pregnant women. Outcomes revealed a correlation of increased cumulative dose, early pregnancy first course, and broad-spectrum antibiotic exposure with childhood asthma risk. Dose-dependent association of prenatal antibiotic exposure with increased odds of childhood asthma was observed. No effect of timing of exposure on childhood asthma risk was noted among pregnant women receiving a single antibiotic course. Early exposure to the first course was linked with greater childhood asthma risk among women receiving more than one course. Increased odds of asthma were observed in correlation to broad-spectrum only antibiotic exposure vs narrow-spectrum only antibiotic use. Findings thereby emphasize using prenatal antibiotics judiciously; the clinician should especially consider the timing of use and choice of antibiotics, in preventing subsequent childhood asthma.