Birth weight, stress, and symptoms of depression in adolescence: evidence of fetal programming in a national Canadian cohort.

Objective: To investigate evidence of fetal programming in humans by studying whether adolescents born at high or low birth weights (LBW) are more likely to experience symptoms of depression and anxiety after experiencing stress.

Method: The sample included 3732 members of a prospective Canadian cohort study assessed for symptoms of depression and anxiety at age 12 to 15 years (2006/2007), and had birth weight and gestational age (GA) data recorded in 1994/1995. Major stressful life events and chronic stressors were also reported throughout childhood.

Results: After adjusting for acute and chronic stress, being born small for GA (SGA) (OR 1.50; 95% CI 1.08 to 2.08) or large (OR 1.31; 95% CI 0.99 to 1.72) for GA was associated with an increased risk of depression and anxiety in adolescence, compared with adolescents who were born at a weight appropriate for their GA. Most interactions between birth weight and stress were not significant; however, the relation between chronic stress and adolescent depression and anxiety was more pronounced in males who were born SGA (interaction P < 0.05).

Conclusions: The link between birth weight and depression is complex and evidence of fetal programming is inconsistent; however, people born at LBW may be at an increased risk of depression in the face of chronic stress.