The retrospective review by Weinstock (2005) focuses on the hypothalamic-pituitary-adrenal (HPA) system. While the sympathetic adrenal medullary (SAM) system handles immediate 'fight-or-flight' arousal, the HPA system is more drawn-out and releases cortisol to restore the body. Over-activation of the HPA system can cause long-term regulatory issues with excess cortisol. Because the fetus is highly vulnerable to its hormonal environment, Weinstock (2005) assumes that prolonged maternal stress and excess cortisol alter fetal development, predisposing offspring to various disorders.