‘Neonates do not feel pain’: a critical review of the evidence

Abstract

Up until 1985, the nervous system of the neonate was widely considered to be underdeveloped for pain sensation. Analgesia to alleviate distress from ‘painful’ procedures in which neonates were, and still are, subject to was often considered trivial. Pain in the neonate and (in some cases) the disabled neonate is especially hard to investigate, as they are unable to verbally communicate. There is also no known direct biological marker of pain, only behavioural and stress-related physiological correlates. This critical review gives evidence for and against the hypothesis ‘Neonates do not feel Pain’. Evidence of both the neonatal response to analgesics and long-term effects of neonatal pain are also investigated, with the aim of further supporting or falsifying the hypothesis. Convergence of the observations covered in this review show that most, if not all, studies are in favour of pain-related behaviour and physiology in the neonate, both of which having a similar phenotype to that seen in the older infant and adult. The evidence investigated in this review also supports the hypothesis that cortical development appears to accommodate the subjectivity of pain, but it is not vital for pain experience. Further data and theory have the potential to bring more invaluable evidence to the table regarding whether or not the neonate is able to feel pain.