Fetal growth predicts stress susceptibility independent of parental education in 161 991 adolescent Swedish male conscripts.

Psychosocial stress could lead to a wide range of possible physiological reactions, due to both the total burden of stress as well as individual susceptibility. Two useful Swedish registers to investigate early life influences on stress susceptibility are the Swedish Medical Birth Register (MBR) and the Military Service Conscription Register (MSCR). In a previous study we showed a positive relation between fetal growth and psychological functioning (PF) including an assessment of stress susceptibility.1 However, in that study we did not adjust for family social class—nor did another related study.2 We have therefore now carried out such an analysis in an expanded cohort study, by adding parental educational level as a marker of family social class. The aim was to investigate independent associations between fetal growth and stress susceptibility in young men.