Kynurenine levels in the maternal plasma (A), placenta (B), fetal plasma (C) and fetal brain (D) 90 minutes after oral treatment of pregnant CD-1 mice on ED18 with either saline (vehicle), kynurenine (100 mg/kg) or KYNA (10 mg/kg). Data are the mean ± SEM (n=3 dams per group; n=3 embryos per dam). **p<0.01, ***p<0.001 (one-way Anova, followed by Bonferroni’s post-hoc test).