Electromagnetic fields generated by hospital incubators influence the heart rates of newborns, say Italian researchers, who call for more research on the impact of such fields on premature babies.

Dr Carlo Bellieni, from the Department of Pediatrics, Obstetrics and Reproductive Medicine of the University of Siena, and colleagues studied the impact of fields from an incubator's electric motor on the autonomic nervous system of newborns.

"EMFs [electromagnetic fields] produced by incubators influence newborns heart rate variability showing an influence on their autonomous nervous system," report the researchers, in the Archives of Disease in Childhood Fetal and Neonatal Edition.

"More research is needed to assess possible long-term consequences, since premature newborns may be exposed to these high EMFs for months."

The autonomic nervous system helps the body adapt to changes in the environment by adjusting or regulating stress responses.