Skin-to-skin contact to support preterm infants and reduce NICU-related stress

Hospitalization in the neonatal intensive care unit (NICU) with numerous painful medical interventions, being separated from parents, leads to the high risk of chronic stress for preterm infants. Today, many NICUs use more appropriate developmental care and pain management, but the early and long-term outcomes of stress in these vulnerable infants require searching for more stress-reducing interventions in neonatal care. The objective of the study was to investigate how skin-to-skin contact (SSC) can influence the biologic stress levels in preterm infants in the NICU by assessing cortisol and oxytocin levels.

The study included 71 preterm infants with gestational age less than 34 + 0/7 weeks who were recruited from level III NICU. The overall design was a baseline-response design. Saliva and urine were collected before (baseline) and after skin-to-skin contact to measure salivary cortisol and urinary oxytocin by enzyme immunoassay method.

The infants' baseline hormonal status was represented by the following indicators: the level of salivary cortisol was 0.402 [0.227; 1,271] μg/dl, urinary oxytocin 48.88 [32.97; 88.11] pg/ml. There was a decrease in salivary cortisol levels to 0.157 [0.088; 0.351] μg/dl compared to baseline (p ˂ 0.001) with a simultaneous increase of the urinary oxytocin level -73.59 [45.18; 108.8] pg/ml (p = 0.028) in response to SSC.

Preterm infants in the NICU experience significant stress, characterized by hormonal imbalance: an increased level of the stress hormone cortisol and a decreased level of the anti-stress hormone oxytocin. Skin-to-skin contact helps to ameliorate the hormonal stress in preterm infants by activating the oxytocin release with simultaneous reduction of cortisol secretion.