Biological and psychosocial predictors of mother-infant bonding and emotional availability at six months postpartum among at-risk mothers.

BACKGROUND

The mother-infant relationship is critical for child development, but may be compromised among mothers facing multiple vulnerabilities. In Singapore, family structures and caregiving norms are rapidly evolving, and at-risk mothers often experience heightened stress and limited social support.

AIM: To understand how psychosocial and biological factors influence mother-infant emotional availability (EA) and bonding.

METHODS

We conducted a cross-sectional study involving 68 at-risk mother-infant dyads drawn from the control arm of a randomized controlled trial in Singapore. Mothers completed validated questionnaires including the Mother-to-Infant Bonding Scale (MIBS), Edinburgh Postnatal Depression Scale (EPDS), State-Trait Anxiety Inventory (STAI), Perceived Stress Scale (PSS), and What Being the Parent of a Baby Is Like (WPBL). Mother-infant interactions were video-recorded and assessed using the EA Scales. Maternal salivary cortisol was collected as a stress biomarker during the six-month postpartum home visit.

RESULTS

Higher continuous maternal salivary cortisol was significantly associated with poorer mother-infant bonding (β = 0.56, p = 0.045). Compared with the middle tertile, the lowest tertile had higher EA scores (B = 7.16, p = 0.007) and greater odds of emotional availability (OR = 5.28, p = 0.019). Greater parenting satisfaction was associated with stronger bonding (β = -1.31, p < 0.001).

CONCLUSIONS

Biological and psychosocial factors may relate differently to distinct dimensions of the mother-infant relationship among at-risk mothers. Higher salivary cortisol was linked to greater bonding difficulties, whereas emotional availability showed a non-linear pattern across cortisol tertiles. Greater parenting satisfaction was linked to more favourable relational outcomes.