Associations Between Nurse-Guided Variables and Plasma Oxytocin Trajectories in Premature Infants During Initial Hospitalization

Abstract

Background: Oxytocin (OT) is a social hormone that may help researchers understand how nurse-guided interventions during initial infant hospitalization, such as supporting human milk expression, promoting comforting touch, and reducing exposure to stressors, affect preterm brain development. Purpose: To determine whether factors related to human milk, touch, or stressor exposure are related to plasma OT trajectories in premature infants. Methods: Plasma from 33 premature infants, born gestational ages 25 to weeks, was collected at 14 days of life and then weekly until 34 weeks' corrected gestational age (CGA). Variables related to feeding volumes of human milk and formula; touch, as indexed by skin-to-skin contact (SSC) and swaddled holding; and clinical stressors were extracted from the electronic medical record. Linear mixed-models tested associations between nurse-guided variables and plasma OT trajectories. Results: In the final model, same-day SSC was positively related not only to plasma OT levels at 27 weeks' CGA (β= .938, P = .002) but also to a decline in plasma OT levels over time (β=−.177, P = .001). Volume of enteral feeds (mL/kg/d), its interaction with CGA, and number of stressful procedures were not statistically significant (β= .011, P = .077; β=−.002, P = .066; and β= .007, P = .062, respectively). Implications for Practice: Nurse-guided interventions are associated with infant plasma OT levels, suggesting nurses may impact the neurobiology of the developing premature infant. Implications for Research: Replication with larger sample sizes and randomized controlled trial designs is needed to test effects of specific nursing interventions on infant OT.