Mother infant cortisol levels and maternal childhood adversity

Area of Science:

• Neuroendocrinology
• Developmental Psychology
• Stress Physiology

Background:

• Cortisol is a key biomarker for the hypothalamus-pituitary-adrenal (HPA) axis, crucial for stress regulation and neurodevelopment.
• While maternal and infant cortisol links are known, their synchrony in early infancy requires further investigation.
• Early infancy is a critical period for rapid neuroendocrine development and stress system maturation.

Purpose of the Study:

• To examine cortisol coupling between mothers and infants during early postpartum development.
• To investigate the correlation between maternal adverse childhood experiences (ACEs) and maternal/infant cortisol dynamics.
• To understand the longitudinal changes in HPA axis synchrony from 1 to 6 months postpartum.

Main Methods:

• Longitudinal study of 305 mother-infant dyads in São Paulo, Brazil.
• Salivary cortisol measurements at approximately 1 and 6 months postpartum.
• Bivariate latent change score modeling to assess intra- and interindividual cortisol dynamics and coupling.

Main Results:

• Positive correlation between maternal and infant cortisol at 1 month (r=0.319) and 6 months (r=0.208), indicating early synchrony that diminishes.
• Negative self-feedback observed in both mothers and infants: higher baseline cortisol predicted smaller changes.
• Maternal ACEs predicted higher baseline maternal cortisol (B=0.126) but did not influence the rate of change.

Conclusions:

• Mother-infant cortisol synchrony is present in early infancy but gradually decouples.
• Maternal adversity, indicated by ACEs, has lasting effects on postpartum maternal stress physiology.
• Findings underscore the importance of maternal HPA axis regulation for infant neuroendocrine development.