The specific mechanism by which maternal psychological distress is transduced to the fetus in order to incur beneficial or deleterious effects is unknown. The most commonly discussed involve consequences of activation of the HPA and sympathetic-adrenomedullary
(SAM) axes. Fetal effects may be generated by placental transfer of glucocorticoids or
Prenatal Distress and Child Development 583 neurotransmitters with resultant alterations to regulatory feedback systems that may have consequences for specific brain regions (Kaiser & Sachser,2005; Mulder et al., 2002).