Maternal mood and concordant maternal and infant salivary cortisol during heel lance while in kangaroo care

Maternal kangaroo care (MKC) is a naturalistic intervention that alleviates neonatal pain, and mothers are assumed to play a stress regulatory role in MKC. Yet, no MKC infant pain study has examined relationship between maternal and infant stress reactivity concurrently, or whether post-partum depression and/or anxiety (PPDA) alters maternal and neonatal stress response and the regulatory effects of MKC.

To examine the concordance of salivary cortisol reactivity between 42 mothers and their stable preterm infants during routine infant heel lance (HL) while in MKC and to compare salivary cortisol between groups of mothers with and without PPDA and their infants.

Maternal and infant salivary cortisol samples were collected pre-HL and 20 min post-HL with two additional maternal samples at night and in the morning. Mothers and infants were allocated to with PPDA versus without PPDA study groups on the basis of maternal post-natal mental health assessment scores.

Higher mothers' cortisol pre-HL was weakly associated with higher infants' salivary cortisol in response to the HL procedure. Maternal depression and/or anxiety were not associated with infants' cortisol. During HL, both groups of mothers and infants showed no change in salivary cortisol.

Concordance between mother and infant salivary cortisol supports the maternal stress regulatory role in MKC. MKC may have stress regulatory benefits for mothers and their preterm infants during HL independent of PPDA. Future MKC studies that target mothers with altered mood will help to build on these findings.