The association between maternal interaction and infant cortisol stress reactivity among preterm and full term infants at 4 months adjusted age.

•Preterm infants demonstrated a more blunted cortisol stress reactivity response compared with full term infants.•Preterm infants had greater variability in their stress reactivity compared with full term infants.•Mothers of preterm infants demonstrated less contingent maternal interaction after infants were initially stressed.•Contingent maternal interaction during Reunion#2 was protective against stress reactivity.•Term group did not moderate the association between contingent maternal interaction and infant cortisol stress reactivity.