Electromagnetic fields produced by incubators influence heart rate variability in newborns

carlo bellieni ^1*, maurizio acampa ², marianna maffei ³, silvia maffei ², sara perrone ⁴, iole pinto ⁵, nicola stacchini ⁶ and giuseppe buonocore ⁷

¹ dept. Pediatrics, Obstetrics and reproductive Medicine, University of siena, italy, Italy
² Department of Clinical Medicine and Immunological Sciences, Section of Internal Medicine, University, Italy
³ department of pediatrics, obstetrics and reproduction medicina, university of siena, Italy
⁴ university of siena, Italy
⁵ departmento of physics, USL 7, siena, Italy
⁶ department of physics siena, Italy
⁷ department of pediatrics, university of siena,, Italy

^* To whom correspondence should be addressed. E-mail: bellieni{at}iol.it.

Accepted 14 February 2008

Abstract

Incubators are largely used to preserve preterm and sick babies from postnatal stressors, but their 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 hear 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 msec2 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±118.1msec2 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.