Abstract
Stress has significant consequences throughout the lifetime. However, when it occurs early in life, the implications may be particularly profound and long lasting. Evidence suggests that high levels of maternal stress during pregnancy are associated with alterations in the normal activity of the maternal hypothlalamic-pituitary-adrenocortical (HPA) and placental axis. Increased activity of this system is related to shortened gestation and impaired fetal growth, factors that place infants at a greater risk for a wide variety of developmental problems. In addition to the implications for birth outcome, our findings suggest that prenatal exposure to stress and stress hormones directly influences development of the fetal central nervous system (CNS). Fetuses who are exposed to disregulated production of stress hormones display impaired learning. Elevated levels of stress or stress hormones during pregnancy are also associated with more difficult infant temperament and disruption of infant HPA axis activity. These data suggest that prenatal experiences can have lasting implications for development.