Flanigan C, et al. - The link between prenatal maternal psychosocial stress and risk of asthma and allergy in the offspring was studied, given prenatal maternal stress may influence offspring's atopic risk through sustained cortisol secretion resulting from activation of the hypothalamic-pituitary axis (HPA), leading to Th2-biased cell differentiation in the foetus. Exposure to prenatal maternal psychosocial stress was shown to be related to increased risk, albeit modestly, of asthma and allergy in the offspring. During the third trimester, the pronounced risk was noted to be a possible representative of cumulative stress exposure throughout pregnancy rather than trimester-specific effect.