Electrical Grounding Improves Vagal Tone in Preterm Infants

Area of Science:

• Neonatal physiology
• Bioelectricity
• Autonomic nervous system function

Background:

• Low vagal tone (VT) is linked to stress vulnerability and necrotizing enterocolitis risk in preterm infants.
• Neonatal intensive care unit (NICU) equipment generates electric fields, creating measurable skin potentials.
• Electrical grounding reduces skin potential and improves VT in adults.

Purpose of the Study:

• Measure NICU electric field strengths.
• Determine if electrical grounding (EG) reduces infant skin potential and improves VT.
• Correlate skin potential with VT.

Main Methods:

• Measured environmental magnetic flux density (MFD) around incubators.
• Applied electrical grounding (EG) using patch electrodes and ground outlets.
• Recorded skin potential and heart rate variability (HRV) for VT assessment in infants before, during, and after EG.

Main Results:

• NICU incubators showed elevated MFD (1.5–12.7 mG).
• All infants exhibited a 60-Hz oscillating skin potential.
• EG reduced skin voltage by ~95% and increased VT by 67%.
• Pre-grounding VT inversely correlated with skin potential.

Conclusions:

• The NICU electrical environment impacts infant autonomic balance.
• EG enhances VT, potentially improving stress resilience.
• EG may reduce the risk of neonatal morbidity in preterm infants.