Grant: Travel Awards - Institute Community Support

Psychological stress is capable of altering the body's immune system, but, it is unknown if experiencing psychological stress during pregnancy affects the development of the fetal immune system and what are the long term consequences of such exposure. Project Ice Storm has been following a group of children born from mothers exposed to psychological stress caused the 1998 Ice Storm in Quebec for more than 15 years. We have shown that stress during pregnancy can produce changes in the child's body and psychological functioning. We are currently investigating how stress during pregnancy changes the development of the baby's immune system, and establish what type of changes are produced. When the participants were thirteen years old, we took samples of their blood to analyzed two important indicators of immunity: the proportion of the main types of immune cells, and cytokines, the molecules through which immune cells communicate with each other. We observed that higher levels of stress in the pregnant mother are related to a small but noticeable reduction of the proportion of T helper cells, which control the type of reaction that the immune system produces facing an infection. T helper cells control other immune cells through the production of cytokines. We also found that higher levels of stress in the pregnant mother induce higher levels of two different groups of cytokines. One group increases inflammation, and the other is normally related with immune responses against parasites, but also associated with allergies and asthma when these cytokines are excessive. The results obtained from our research provide a link between stress in the pregnant mother and health in her child long after birth. This information has an enormous potential for the guidance and implementation of preventive and interventional strategies that could reduce the frequency of diseases associated with the immune system, in this particular case, allergies.