The effect of mother-infant skin-to-skin contact on plasma cortisol and β-endorphin concentrations in preterm newborns

Abstract

The aim of this study was to assess the effect of mother-infant skin-to-skin contact on plasma β- endorphin and cortisol concentrations in stable, preterm infants on a newborn intensive care unit. Blood samples were obtained before and at the end of a 20-min period of skin-to-skin contact. Similarly paired samples, obtained at the same times and after the same interval, without skin-to- skin contact, were obtained on another day and served as controls. Both cortisol and β-endorphin concentrations fell significantly after the skin-to-skin session (cortisol: geometric mean change 66%, p=0.008; β-endorphin: geometric mean change 74%, p=0.002). There was also a significant fall in cortisol levels during the control session (geometric mean change 78%, p=0.02), in contrast to β-endorphin levels, in which there was no significant change. Analysis of variance showed that the fall in β-endorphin, but not the fall in cortisol, during the skin-to-skin session was significant when compared with the control session. These results emphasize the hormonal responsiveness of the preterm newborn to relatively minor interventions. We conclude that maternal skin-to-skin contact results in a significant reduction in circulating β-endorphin in the newborn; there was no evidence of any adverse effect.