The effect of massage on heart rate variability in preterm infants.

Smith, S L; Lux, R; Haley, S; Slater, H; Beachy, J; Moyer-Mileur, L J

OBJECTIVE To test the hypothesis that massage would improve autonomic nervous system (ANS) function as measured by heart rate variability (HRV) in preterm infants. STUDY DESIGN Medically stable, 29- to 32-week preterm infants (17 massage, 20 control) were enrolled in a masked, randomized longitudinal study. Licensed massage therapists provided the massage or control condition twice a day for 4 weeks. Weekly HRV, a measure of ANS development and function, was analyzed using SPSS generalized estimating equations. RESULTS Infant characteristics were similar between groups. HRV improved in massaged infants but not in the control infants (P<0.05). Massaged males had a greater improvement in HRV than females (P<0.05). HRV in massaged infants was on a trajectory comparable to term-born infants by study completion. CONCLUSION Massage-improved HRV in a homogeneous sample of hospitalized, medically stable, preterm male infants and may improve infant response to exogenous stressors. We speculate that massage improves ANS function in these infants.