Electromagnetic fields alter infant heart rate

Electromagnetic fields generated by incubators in hospital nurseries affect heart rates in newborns, suggesting that such fields are capable of altering autonomic nervous system activity. The autonomic nervous system helps the body adapt to changes in the environment by adjusting or regulating stress responses. These functions take place "automatically" or "involuntarily" and include, but are not limited to, adjustments in blood vessel size, fluctuations in blood pressure, and the generation of electrical activity, such as the electrical signal that makes the heart muscle contract, and keeps the heart beating. To verify whether the exposure to incubator motor electric power may alter autonomous nervous system activity in newborns, researchers in Italy evaluated heart rate variability in 43 newborns while in incubators, none of whom were premature or critically ill. Heart rate variability refers to the normal alterations in heart rate that occur under resting conditions, and in other circumstances, in healthy individuals. Reduced heart rate variability is therefore a sign of some cardiac abnormality. Among the 43 newborns, 27 underwent heart rate variability testing for 5-minute intervals while an incubator motor was on, off, and on again. The remaining 16 infants were not exposed to an incubator motor, but were exposed to audio stimuli mimicking the sounds of a motor. When the incubator motor was turned off, total power and the high-frequency component of heart rate variability increased, while the low frequency / high frequency ratio decreased. Turning on the motor again restored the balance. The low frequency spectral component of heart rate variability changed significantly, but only when the motor was turned on the second time. Heart rate variability did not change in the group of infants exposed to changing background. The findings suggest that though long-term impact of electromagnetic field exposure is unclear, it could have implications for preterm infants who often spend several weeks in incubators. Thus, newborns should have protection levels similar to those set by International recommendations and laws to safeguard the health of workers exposed to electromagnetic fields. And preterm infants should be periodically evaluated, with particular attention to the development of the autonomic nervous system.