Effect of Cue-based Tactile Stimulation on Premature, Low Birth Weight Infants: Stress Reactivity.Immune Functioning, and Parenting

The overarching aim of this study is to assess the effects of a program of mother-delivered, cue-based infant massage on stress reactivity in the mother-infant dyad, and on other measures of mother-infant functioning. The study has several interrelated objectives:

1. To evaluate the short-term effects of infant massage intervention on infant and maternal stress reactivity from assays of maternal and infant salivary cortisol, and cortisol levels in mothers' breast milk.
2. To examine the impact of mother-delivered infant massage on the development of infant resistance to infectious pathogens and antibody-based protective immunity in response to routine scheduled vaccinations, and to examine if the degree of immunity is mediated by infant stress reactivity.
3. To examine the impact of mother-delivered infant massage, and of changes in stress reactivity in response to massage, on infant physiological functioning (vagal tone, heart rate variability), infant physical development (weight, height, and head circumference), mothers' perception of infant temperament and infant state regulation, parenting self-efficacy, symptoms of depression and anxiety, and mother-infant interaction.
4. To examine associations between cortisol levels in mothers' saliva, mothers' breast milk, and infants' saliva. Establishing such linkages would support recent animal data suggesting that infant glucocorticoid levels can be affected by glucocorticoid levels transferred to the infant in mother's milk.
5. To examine whether a single nucleotide polymorphism (SNP) in three candidate genes (Mu opioid receptor, brain-derived neurotropic factor, and vasopressin V1b receptor), each associated with hypothalamic-pituitary-adrenal axis (HPA) functioning, moderates the effects of infant massage on stress-related outcomes.