The developmental origins of stress reactivity: an intergenerational life-course perspective

Intergenerational effects of maternal childhood maltreatment on newborns' stress regulation: The role of maternal depressive symptoms

BACKGROUND

Maternal childhood maltreatment (CM) has been repeatedly associated with negative offspring's emotional outcomes. The dysregulation of the Hypothalamic-Pituitary-Adrenal (HPA) axis has emerged as the main underlying physiological mechanism.

OBJECTIVE

To explore the association between maternal CM and newborns' physiological and neurobehavioral stress responses, considering the role of perinatal maternal depression and bonding.

PARTICIPANTS AND SETTING

150 healthy women were followed throughout pregnancy. 79 mother-infant dyads were included in the final analyses. Maternal CM was evaluated using the Childhood Trauma Questionnaire and depressive symptoms by the Edinburgh Postnatal Depression Scale (EPDS) at each trimester. At 7 weeks postpartum, the EPDS and the Postpartum Bonding Questionnaire were administered. Newborns' behavioral responses were assessed using "States Organization" (SO) and "States Regulation" (SR) subdomains of the Neonatal Behavioral Assessment Scale (NBAS). Newborns' salivary samples were collected before and after the NBAS to study cortisol reactivity.

METHODS

A cross-lagged panel model was employed.

RESULTS

Infants born to mothers with higher CM presented more optimal scores on SO (β (0.635) = 0.216, p 〈001) and SR (ß (0.273) = 0.195, p = .006), and a higher cortisol reactivity after NBAS handling (β(0.019) = 0.217, p = .009). Moreover, newborns of mothers with higher CM and postpartum depressive symptoms exhibited a poorer performance on SR (ß (0.156 = -0.288,p = .002). Analyses revealed non-significant relationships between mother-infant bonding, newborns' cortisol reactivity and SO.

CONCLUSIONS

Newborns from mothers with greater CM present higher cortisol reactivity and more optimal behavioral responses, which may reflect a prenatal HPA axis sensitization. However, those exposed to maternal postnatal depressive symptoms present poorer stress recovery.

Maternal Early Life Adversity and Infant Stress Regulation: Intergenerational Associations and Mediation by Maternal Prenatal Mental Health

Early life adversity is a potent risk factor for poor mental health outcomes across the lifespan, including offspring vulnerability to psychopathology. Developmentally, the prenatal period is a sensitive window in which maternal early life experiences may influence offspring outcomes and demarcates a time when expectant mothers and offspring are more susceptible to stressful and salutary influences. This prenatal plasticity constituted the focus of the current study where we tested the association of maternal early life adversity with infant stress regulation through maternal prenatal internalizing symptoms and moderation by prenatal social support. Mother-infant dyads (n = 162) were followed prospectively and mothers completed assessments of social support and depressive and anxiety symptoms across pregnancy. Infants completed standardized stress paradigms at one month and six months. There were several key findings. First, maternal prenatal depressive symptoms significantly mediated predictions of infant cortisol reactivity to the heel stick at one month from maternal early life adversity: specifically, maternal early life adversity positively predicted depressive symptoms in pregnancy, which in turn predicted dampened infant cortisol reactivity. Second, prenatal social support did not significantly moderate predictions of depressive or anxiety symptoms in pregnancy from maternal early life adversity nor did it alter the associations of maternal depressive or anxiety symptoms with infant stress regulation. These results suggest that maternal prenatal mental health is a key mechanism by which maternal early life adverse experiences affect offspring risk for psychopathology. We discuss potential clinical and health implications of dysregulated infant cortisol reactivity with respect to lifespan development.