This editorial appeared in the Nov 1996 Edition of the CMQ
Return to Nov 1996 CMQ
DOES THE FETUS FEEL PAIN
Interest in this problem has arisen from a questionnaire recently submitted to 151 members of the Association of Paediatric Anaesthetists of Great Britain and Ireland asking them whether they thought newborn infants of less than 1 week of age, neonates aged 1 week to 1 month, and infants of less than 60 weeks post conceptual age who were delivered preterm (before 37 weeks) were able to feel pain.(1) It was designed to allow comparison with a similar survey conducted in 1988. In that survey eight (13%) respondents thought that newborn infants and four respondents (7%) that neonates did not feel pain. Fourteen (23%) in 1988 were undecided. In contrast the new survey reveals that all the anaesthetists believe that the newborn suffer pain and nine out of ten always or usually use systemic opioids when newborn infants are having major surgery. Such a remarkable change of opinion has created a poignant background to the question of whether the fetus can feel pain.
The received opinion of the Department of Health, based on a paper by Fitzgerald which reviewed the biological development of the fetus, ruled out the possibility of a fetus experiencing pain before 26 weeks of gestation.(2) The recorded responses to stimulation before 26 weeks were described as reflex, not dependent on conscious appreciation. It is assumed that reflexes provoked by tactile stimulation or light pressure are not pain sensitive. Another commonly held view is that, as the cortex is not developed, how is it possible for pain to be experienced?
Such opinions are seriously and effectively challenged in the paper included in this issue based on the work of Peter McCullagh and others, including members of the Guild.
The International Association for the Study of Pain defines pain as 'an unpleasant emotional experience associated with actual or potential tissue damage'. This is fine, points out Dr. McCullagh, when it is applied to a communicative human subject with a good vocabulary. But how is the emotional context of 'pain' in a young animal to be evaluated? Is pain, as defined by the IASP, to be restricted only to those species in which we know something about the emotional accompaniment? It seems improbable, and is certainly unknowable, whether a new- born kitten that has been injured has the experiential and emotional accompaniment that influences pain perception in a mature human subject. Nevertheless, there is widespread belief in the community that to inflict injury on the kitten is wrong. (3)
Again, observed human fetal avoidance responses are often dismissed as withdrawal reflexes only because of the assumption that mature cortical function is essential for sentience. Yet opinions concerning the extent (if any) of cortical development required for the awareness of unpleasant sensations represent conjecture. There are abundant indications that individuals with grossly disrupted cortical development can experience pain.
References:
- Jonathan de Lima et al., Infant and neonatal pain: anaesthetists' perceptions and prescribing pattern, BMJ, 313, 28/9/96.
- Fitzgerald M. for the Department of Health, Fetal pain: an update of scientific knowledge, London: DoH, 1995.
- McCullagh P., Determining fetal sentience, Hospital Update, January 1996.