Hormonal and Neuromuscular Responses to Breastfeeding: A Pilot Study:

Objectives:Difficult breastfeeding in the first weeks after birth may result in muscle tension in infants and activation of the maternal hypothalamic–pituitary–adrenal (HPA) axis and sympathetic nervous system (SNS). Our primary objective was to examine the feasibility of collecting neuroendocrine markers of maternal HPA axis and SNS activation (salivary cortisol and α-amylase [sAA]) and electromyographic (EMG) markers of infant distress during feeding in the first 2 weeks after birth. We also examined the relationships of these indices to each other and to mother–infant interactive behaviors during feeding.Methods:We recruited mothers in the postpartum unit of a teaching hospital and observed a feeding in the dyad’s home. Cortisol and sAA were sampled before feeding, 10 min into feeding, at feeding end, and 20 min after feeding. Infant muscle activity was recorded continuously with an EMG data logger. We used the Nursing Child Assessment Feeding Scale to measure mother–infant interaction.Results:The 20 m...