Comparison of salivary cortisol, heart rate, and oxygen saturation between early skin-to-skin contact with different initiation and duration times in healthy, full-term infants

Background: There are few studies that compare the physiological and biological efficacies between different early skin-to-skin contacts (SSC) post birth.

Aim: To investigate physiologically and biochemically how early SSC with different initiation and duration time influence the stress post birth for full-term infants.

Study design: Non-experimental study.

Subjects: Study I; Thirty-two infants who began SSC 5 min or less [birth SSC, mean initiation time (standard deviation): 1.6 (1.1) min] after birth and 36 infants who did so more than 5 min [very early SSC, 26.3 (5.0) min] in heart rate (HR) and oxygen saturation (SpO(2)) analysis. Study II; Eighteen infants who underwent SSC for 60 min or less [mean initiation time: 7.5 (12.2) min] and 61 infants who did so for more than 60 min [15.3 (12.5) min] in salivary cortisol analysis.

Outcome measures: HR and SpO(2) measured for 30 min post birth. Salivary cortisol concentration measured at 1 min, 60 min, and 120 min post birth.

Results: Birth SSC group reached HR stability of 120-160 bpm significantly faster than very early SSC group by Kaplan-Meier analysis (P=0.001 by log-rank test). As for SpO(2) stability of 92% and 96%, no significantly between-group difference was found. Salivary cortisol levels were significantly lower between 60 and 120 min after birth in SSC group, continuing for more than 60 min compared with SSC group for 60 min or less after adjustment for salivary cortisol level at 1 min besides the infant stress factors (P=0.046).

Conclusions: Earlier SSC beginning within 5 min post birth and longer SSC continuing for more than 60 min within 120 min post birth are beneficial for stability of cardiopulmonary dynamics and the reduction of infant stress during the early period post birth.