Incubators’ motors produce high electromagnetic fields (EMFs). Newborns are chronically exposed to these EMFs, but no studies about their effects on the fragile developing neonatal structure exist.

Aim To verify whether the exposure to incubator motor electric power may alter autonomous nervous system activity in newborns.

Material and Methods We studied heart rate variability (HRV) in 43 newborns while in incubators. The study group was composed of 27 newborns whose HRV was studied throughout three 5-minute periods: with incubator motor on, off, and on again, respectively. Mean HRV values obtained during each period were compared. The control group was composed of 16 newborns with constantly unrecordable EMF and exposed to changes in background noise, similar to those provoked by the incubator motor.

Results Mean total power and HF (high frequency) component of HRV increased significantly (from 87.1±76.2 to 183.6±168.5 msec²) and mean LF/HF (low/high frequency) ratio decreased significantly (from 2.0±0.5 to 1.5±0.6) when the incubator motor was turned off. Basal values (HF = 107.1±118.1 msec² and LF/HF = 1.9±0.6) were restored when incubators were turned on again. The LF spectral component of HRV showed a statistically significant change only in the second phase of the experiment. Changes in background noise did not provoke any significant change in HRV.

Conclusion EMFs produced by incubators influence newborns’ HRV, showing an influence on their autonomous nervous system. More research is needed to assess possible long-term consequences, since premature newborns may be exposed to these high EMFs for months.