615 - Biobehavioral Efficacy of the Side-lying Position for Feeding Preterm Infants

Publication Number: 2600.615

Jinhee Park, Boston College, Chestnut Hill, MA, United States; Melissa McTernan, Boston College, Boston, MA, United States; Jane Smallcomb, Beth Israel Deaconess Medical Center, Plymouth, MA, United States; Maria Laura Mourão, Beth Israel Deaconess Medical Center, Boston, MA, United States; Suzanne Thoyre, University of North Carolina at Chapel Hill School of Nursing, Chapel Hill, NC, United States

Background: The side-lying position is hypothesized to improve feeding safety by creating conditions that support physiological stability and oral feeding efficiency. Although widely used in Neonatal Intensive Care Units (NICUs) for bottle-feeding preterm infants, high-quality evidence supporting this practice is limited.

Objective: This study aimed to establish an evidence base by: (1) comparing physiologic responses and feeding outcomes to the traditional supine position, and (2) exploring infant characteristics as moderators to identify subgroups that benefit most.

Design/Methods: A randomized cross-over design was used with preterm infants (≤35 weeks’ gestational age) in a Level III NICU transitioning to full oral feeding. Each infant served as their own control across two consecutive feedings (within 24 hours): one in the supine and one in the side-lying position. Continuous cardiorespiratory data—heart rate (HR), oxygen saturation (SaO₂), and respiratory rate (RR)—were collected from 30 minutes before to 30 minutes after feeding. Oral feeding skills were assessed using the Early Feeding Skills (EFS) tool from videotaped sessions. Linear mixed-effects models accounted for the repeated-measures, cross-over design, and infant characteristics (sex, maturity, and medical complications) were examined as potential moderators.

Results: Infants fed in the side-lying position demonstrated greater physiological stability and improved oral feeding skills compared with those fed in the supine position. Physiological Stability: Side-lying was associated with more stable breathing (lower coefficient of variation of RR; p=0.009), a smaller percentage of feeding time with prolonged breathing pauses (p=0.026), fewer occurrences of pauses (p=0.015), and fewer HR drops below 100 bpm (p < 0.001). Oral Feeding Skills: Side-lying produced higher total EFS scores (p < 0.001), with improvements in swallowing coordination and physiological stability subscales. Moderators: Effects of infant characteristics were observed for some physiological outcomes (mean HR and RR), with greater benefits among female infants and those with greater physiological vulnerability, including more severe medical complications, lower maturity at birth, and higher postmenstrual age.

Conclusion(s): Findings provide strong quantitative evidence supporting the clinical use of the side-lying position as a feeding strategy in the NICU. This position appears particularly effective for infants with greater physiological vulnerability, offering evidence-based guidance for clinicians in targeted intervention planning and positioning practices.