Maternal pre-pregnancy body mass index and offspring temperament at 3 months

Introduction: Pre-pregnancy obesity has been linked to emotional and behavioural problems in offspring, though it remains unclear when the presence of these difficulties first emerges. Method: We examined the association between maternal pre-pregnancy body mass index (BMI) and temperament at 3 months of age in the offspring of 16 women residing in Hamilton, Ontario. Infant temperament was measured using the Infant Behaviour Questionnaire Revised, which specifically examined surgency/extraversion, negative affectivity, and orienting/regulation. Results: A statistically significant association was observed between maternal BMI and infant negative affectivity (B=0.05, 95% CI=0.01-0.08), which remained significant after adjusting for confounding variables (B=0.04, 95% CI=0.01-0.08). Conclusion: The current study provides evidence that fetal exposure to high maternal BMI during pregnancy is associated with increased negative affectivity in infants at 3 months of age. The results suggest that the intrauterine environment associated with high maternal BMI may influence temperament at a very early stage in development.