(A) Corticosterone concentrations in maternal sera throughout pregnancy from undisturbed dams: n = 4 for all timepoints. (B) Serum concentration of corticosterone taken immediately after the first (GD2 or GD10) and last (GD9 or GD17) inductions from dams exposed to aerosolized PBS or OVA daily in early or late pregnancy compared to untreated controls. (C) Anti-OVA IgE concentrations in sera from PBS and OVA-exposed dams taken four hours after the final induction in early (G9) or late (G17) gestation. (D) Negative correlation between maternal anti-OVA IgE antibodies and corticosterone concentrations in OVA-treated dams taken at GD10 (Early) and GD17 (Late). * p < 0.05 compared to gestational day-matched untreated control, † p < 0.05 compared to treatment-matched GD9 and GD10, # p < 0.05 compared to GD2 control; all determined by mixed-model ANOVA with Turkey post hoc corrections. Correlation assessed using pearson’s r correlation coefficient. Open dots represent individual mice; bars represent marginal means +/− SE. Early-PBS n = 6-7 (serum was not available from one mouse on GD9 due to technical mistakes), Early-OVA n = 6, Late-PBS n = 7, Late-OVA n = 7.