Figure 5.

Effect modification of maternal asthma status and timing of the first prenatal antibiotic course on the risk of childhood asthma among children exposed to at least 1 course of prenatal antibiotics. Multivariable logistic regression adjusted for maternal age, education, smoking, presence of group B Streptococcus infection, delivery method, and infant characteristics including birth hospitalization length of stay, gestational age, birth weight, infant race, sex, and number of living siblings at home. Gestational age in days at the first course was assessed with restricted cubic splines (3 knots). The gray band around the lines indicates the 95% confidence interval.