Babies feel pain in the same way as adults do, but are more sensitive to it, scientists have discovered in a world-first experiment.
The findings, led by researchers at Oxford University, suggest a review of pain relief for babies should be carried out.
The study, published in the journal eLife, used MRI scans to look at the brains of adults and infants when they were exposed to the same painful stimulus.
Researchers used 10 healthy babies aged between one and six days old, and 10 health adults aged between 23 and 36 years. The team placed the babies inside the MRI machine – most of the time they fell asleep. They were then poked on the bottom of their feet with a soft enough touch that it did not wake them up.
Adults were then exposed to the same pain stimulus and the scientists compared the brain scans.
Findings showed that 18 of the 20 brain regions active in adult brains were also active in the baby brains. They also found they had the same response to being poked at a small force as adults did with a force four times stronger – suggesting babies not only feel pain in the same way, but their threshold is lower.
The authors say their findings have major implications for pain relief in babies – in 2014 a pain review showed that infant surgery patients experience around 11 painful procedures per day, yet 60% receive no form of pain medication.
Lead author Rebeccah Slater said: "Thousands of babies across the UK undergo painful procedures every day but there are often no local pain management guidelines to help clinicians. Our study suggests that not only do babies experience pain but they may be more sensitive to it than adults.
"We have to think that if we would provide pain relief for an older child undergoing a procedure then we should look at giving pain relief to an infant undergoing a similar procedure.
"Obviously babies can't tell us about their experience of pain and it is difficult to infer pain from visual observations. In fact some people have argued that babies' brains are not developed enough for them to really 'feel' pain, any reaction being just a reflex - our study provides the first really strong evidence that this is not the case."