Birth weight is associated with salivary cortisol responses to psychosocial stress in adult life.

Fetal programming of the hypothalamus-pituitary-adrenal (HPA) axis was proposed as one mechanism underlying the link between prenatal stress, adverse birth outcomes (particularly low birth weight) and an enhanced vulnerability for several diseases later in life. In recent studies, birth weight was significantly related to basal cortisol levels as well as to cortisol responses to pharmacological stimulation. In order to investigate the association between cortisol responses to psychological challenge, birth weight and length of gestation, 106 young healthy males were exposed to the 'Trier Social Stress Test'. Salivary cortisol responses to the stress exposure were significantly and inversely related to the subjects' birth weight, while the analysis of the impact of gestational age yielded inconsistent results. This finding is consistent with the concept of fetal programming of the HPA axis and provides the first preliminary evidence for an association between birth weight and adrenocortical responses to psychosocial stress. As the investigated subjects were twins, possible implications of this sample characteristic for the present findings are discussed.