Fetal pain

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Best Practice & Research Clinical Obstetrics and Gynaecology xxx (2010) 1–9

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Best Practice & Research Clinical
Obstetrics and Gynaecology
journal homepage: www.elsevier.com/locate/bpobgyn

8

Foetal pain?
Stuart W.G. Derbyshire, PhD, Senior Lecturer *
University of Birmingham, School of Psychology, Edgbaston B15 2TT, UK

Keywords:
The majority of commentary on foetal pain has looked at the
Pain maturation of neural pathways to decide a lower age limit for
nociception foetal pain. This approach is sensible because there must be
abortion a minimal necessary neural development that makes pain possible.
surgery Very broadly, it is generally agreed that the minimal necessary
human neural pathways for pain are in place by 24 weeks gestation.
development Arguments remain, however, as to the possibility of foetal pain
consciousness
before or after 24 weeks. Some argue that the foetus can feel pain
awareness
earlier than 24 weeks because pain can be supported by subcor-
foetal
tical structures. Others argue that the foetus cannot feel pain at
any stage because it is maintained in a state of sedation in the
womb and lacks further neural and conceptual development
necessary for pain. Much of this argument rests on the definition
of terms such as ‘wakefulness’ and ‘pain’. If a behavioural and
neural reaction to a noxious stimulus is considered sufficient for
pain, then pain is possible from 24 weeks and probably much
earlier. If a conceptual subjectivity is considered necessary for pain,
however, then pain is not possible at any gestational age.
Regardless of how pain is defined, it is clear that pain for
conceptual beings is qualitatively different than pain for non-
conceptual beings. It is therefore a mistake to draw an equiva-
lence between foetal pain and pain in the older infant or adult.
Ó 2010 Elsevier Ltd. All rights reserved.

During the past 10 years there has been increasing legislative interest in the possibility of foetal
pain. In 2006, the US House of Representatives debated the Unborn Child Pain Awareness Act.1 The bill
secured a majority but failed to obtain the two-thirds majority necessary to pass it as a law. Efforts at
the state level have been more successful. At least 25 US states have deliberated on foetal pain

* Tel.: þ44 0121 414 4659; fax: þ44 0121 414 4897.
E-mail address: s.w.derbyshire@bham.ac.uk

1521-6934/$ – see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bpobgyn.2010.02.013

Please cite this article in press as: Derbyshire SW, Foetal pain?, Best Practice & Research Clinical
Obstetrics and Gynaecology (2010), doi:10.1016/j.bpobgyn.2010.02.013

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legislation and at least eight (Alaska, Arkansas, Georgia, Oklahoma, South Dakota, South Louisiana,
Texas and Wisconsin) now have legislation requiring that women seeking abortions be informed of the
possibility of foetal pain.
Foetal pain has also been widely debated in Britain. The British Medical Research Council (MRC) and
the Royal College of Obstetricians (RCOG) have both issued reports on this subject2,3; the issue of foetal
pain was debated upon by the British Parliamentary Science and Technology Select Committee in
2008.4 To the author’s knowledge, however, no British or European legislation makes any direct
reference to foetal pain.
Increasingly invasive surgical and other medical procedures performed in utero have also generated
contemporary interest in foetal pain. Although rare, it is now possible to perform foetal surgery for
conditions such as lower urinary tract obstruction, hydrothorax, cystic adenomatous malformation of
the lung, congenital diaphragmatic hernia, spina bifida and large sacrococcygeal teratomas.5 More
commonly, but still relatively rare, the foetus may be exposed to invasive interventions for the
transfusion of donor red cells into the foetal intrahepatic umbilical vein or the peritoneal cavity. In
addition, drainage of abnormal fluid collections, for example, a dilated bladder or hydrothorax, can be
achieved by a single aspiration using a needle or the percutaneous insertion of an indwelling shunt into
the amniotic cavity. Similarly, endoscopic placement of a balloon that is inflated in the foetal trachea
can be used to improve outcome in cases of congenital diaphragmatic hernia. Finally, surgical abortion
can obviously expose the foetus to intensely invasive procedures.
Resolving the question as to whether the foetus feels pain is not straightforward, most attempts at
answering the question consider the neural pathways that are necessary for pain and ask when those
pathways are present and functional in the foetus.6–10 This approach is useful because it is reasonable
to assume that there is a necessary neural biology that renders pain experience possible. If the foetus
lacks that necessary neural biology then it is reasonable to assume that it cannot feel pain. The
approach is limited, however, by knowledge of the necessary neural biology. Although there is
a general consensus that certain cortical structures are necessary for pain, legitimate arguments that
cortical structures are not necessary continue to be raised.9,11,12 This article will first consider the neural
pathways that might be necessary for pain and then go on to consider the limitations of deciding foetal
pain based on the existence of such pathways.

The neuroanatomy of pain

A considerable amount is known about the biological structures involved in painful experience.
Humans, and many other species, have neural structures that respond preferentially to noxious
stimuli.13–15 Beginning in the periphery, there are nerve endings that preferentially transmit noxious
information. They are the free nerve endings that arise mostly from the peripheral termination of
A-delta and C fibres. The free nerve endings are polymodal and can respond to non-noxious and
noxious temperatures or mechanical stimuli. When activity in A-delta and C fibres gives rise to pain or
behaviour associated with pain then they are labelled as nociceptors. Fibres that only respond in the
noxious range are labelled as nociceptive specific, while those that respond across the noxious and
non-noxious range are labelled as wide dynamic range.
The primary afferent A-delta and C fibres terminate on neurons in the superficial dorsal horn of the
spinal cord. Ascending projections to the thalamus originate from the most superficial layer, known as
lamina I, and project contralaterally in the spinothalamic tract (STT). Intracellular recordings from
lamina I neurons revealed neurons with seemingly modality-specific responses. One class of neurons
were nociceptive specific, responsive only to noxious pinch, heat or both. Another class were
thermoreceptive-specific, responding only to non-noxious cooling. A final class were polymodal,
responding to heat, pinch and cooling. Provocatively, the existence of lamina I neurons, with specific
responses and distinct morphology, motivated the suggestion that there are dedicated pathways for
pain and temperature detection.14
A series of neuroimaging studies have demonstrated consistent activation of several cerebral
structures during pain.16 These structures include the primary and secondary somatosensory cortices
and anterior cingulate, prefrontal and insular cortices. In combination, these structures are thought to
coordinate defensive reactions and generate the sensory and unpleasant feelings associated with pain.


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Thus, a noxious stimulus sets in motion a train of biological events that acts to prevent further injury.
People who lack nociceptors or have other biological deficits associated with the nociceptive system do
not engage in defensive behaviours and do not report experiences of pain.13 Consequently, they suffer
considerable, often life-threatening, injuries.
The first evidence for an intact nociceptive system in the foetus emerges at about 8 weeks gesta-
tional age (GA). At this stage, touching the perioral region will result in movement away, indicating the
presence of sensory receptors and, at least, spinal or brainstem-mediated reflex action.17 Some claim
that by 8 weeks GA, there are connections from the periphery and through the spinal cord to the
thalamus (http://www.abortionfacts.com/online_books/love_them_both/why_cant_we_love_them_
both_14.asp) but these claims are yet to receive any peer-reviewed verification.
At 8 weeks GA, the foetal brain is profoundly immature. There is no indication of maturation
such as cortical sulcation and gyration18 or the appearance of a laminar structure in either the
thalamus or the cortex.19,20 The external wall of the brain is about 1 mm thick, consisting of an
inner and outer layer, but without a cortical plate from which the cortical layers will later develop.21
The cell density of the outer layer is significantly higher than that of a newborn or adult but
contains large neurons that resemble those described in the older foetus. Beginning from about 9
weeks GA, there is thalamic fibre penetration directly into this outer layer that stimulates deve-
lopment and maturation of these large neurons.20 There is speculation that by 11 weeks GA these
projections may be functional. The possibility of functional neurons from the periphery, into the
thalamus and into the outer layer of the developing cortex places a lower time limit for foetal pain
at around 11 weeks GA.
Between 12 and 18 weeks, the formation of the subplate begins and the first projections from
the thalamus into the subplate appear.21–23 The subplate is a transient brain structure formed
directly underneath the developing cortical plate. Neurons arrive in the subplate and are held for
several weeks until the cortical plate becomes growth-permissive and facilitates neuronal invasion
of the cortical plate.24 The relocation of neurons from the subplate to the cortical plate begins
around 24 weeks GA and is extremely rapid from about 34 weeks. Afterwards the extracelluar
matrix and other growth-related and guidance molecules disappear leading to the dissolution of
the subplate.21
Morphological features of maturity can be gradually observed from about 12 weeks GA. At 13
weeks, for example, a linear furrow or groove can be observed at the limit of the temporal lobe below
and the insula, frontal and parietal lobes above.18 Around 15 weeks GA, this groove becomes part of the
insular cortex, which is believed to be the first lateral cortical region to develop and is a key region
involved in the experience of pain.16 The subplate has also been observed to thin in areas where cortical
folding occurs, such as the parieto-occipital sulcus, and in the insula and cingulate gyrus at least from
20 weeks GA.25 It is currently uncertain whether this thinning is due to earlier maturation of these
regions, and potentially earlier synaptic activity in the insula and cingulate cortex, which are both key
areas in the experience of pain16, or due to incidental morphological changes. Nevertheless, before 26
weeks GA, the foetal brain is largely smooth with only minor evidence of sulcation and gyration.
Massive growth of the brain after 34 weeks rapidly results in the characteristic folds and surface
features of the more mature brain.
By 24 weeks GA, substantial thalamocortical afferents have accumulated at the superficial edge of
the subplate, which is the stepping-off point for axons growing towards their final cortical targets.21
Between 24 and 32 weeks there is substantial ingrowth of thalamocortical axons in the cortical
plate of the frontal, somatosensory, visual and auditory cortex and formation of the first synapses in the
deep cortical plate. Clear evidence of synaptic activity following auditory stimulation has been
recorded from around 26 weeks in utero and somatosensory responses have been recorded in
premature neonates of 25 weeks GA following a noxious heel lance.26,27
By around 24 weeks GA, therefore, it can be assumed that noxious peripheral events cause
a response in the primary sensory cortex indicating the presence of a spinothalamic connection. Long
axonal tracts now course from the periphery and through the brain to the cortex. It is generally
accepted that the necessary neural structures for pain are in place and are functional by 24 weeks
GA.6–10 Thus, it is possible that measures to prevent pain might be appropriate during invasive
procedures after 24 weeks GA.


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Further developments

Recently, however, it has become clear that the pre- and post-birth environments are very different
with potentially important consequences for painful experiences. It is also becoming clear that
completion of the major pathways from the periphery to the cortex, at around 24 weeks GA, does not
signal the end of cortical development but rather the beginning of a further maturational process.
In an extensive and important review, Mellor et al. 28 described evidence suggesting that the foetus
never enters a state of wakefulness in utero. This conclusion was based largely on observations of foetal
lambs. Rigatto et al. 29, for example, directly observed an unanaesthetised sheep foetus, in utero, through
a Plexiglas window, for a total of 5000 h without observing signs of wakefulness such as eyes opening or
coordinated movement of the head. Mellor and colleagues suggest several factors explain this lack of
wakefulness including the environment of the womb, which is warm, buoyant and cushioned, and the
presence of a chemical environment that preserves a continuous sleep-like unconsciousness or
sedation. The environment of the womb and the chemical suppression of wakefulness maintain
unconsciousness and suppress higher cortical activation in the presence of intrusive external stimu-
lation. The foetal response to hypoxia and asphyxia, for example, is characterised by apnoea, cessation of
foetal body movements and a shift to a more quiescent Electroencephalographic (EEG) state indicative
of unconsciousness.30,31
A series of studies have also demonstrated that as spinothalamic pathways complete their
connections with the cortex, from around 24 weeks GA, they increasingly stimulate intracortical
pathways into development, which is the next major phase of neuronal maturation. This phase
involves elaboration of dendrites and axons, formation and regression of synaptic connections and
selective elimination of cell populations and corresponds to the cortical maturation described by
Goldman-Rakic32 in primates and by Chugani33 in humans. McKinstry et al. 34 illustrated the effects of
this development using diffusion tensor imaging (DTI) in neonates born at 26 and 35 weeks GA.
Neonates born at 26 weeks GA have a cortical cell structure dominated by radially orientated dendrites
that inhibit the spread of water parallel to the surface of the brain. Consequently, DTI measures an
elongated diffusion of water in the cortex. Neonates born at 35 weeks GA, in contrast, have a cortical
cell structure with radially orientated and basal dendrites that inhibit the spread of water in all
directions. Consequently, DTI measures a spherical diffusion of water in the cortex. This proliferation of
cortical neurons and the overproduction of their arborisation and synaptic contacts begins prenatally,
as illustrated by McKinstry et al.34, but continues postnatally, along with synaptic elimination, pruning
and programmed cell death.32,33,35,36
The sedation of the foetus in utero, and the further development of the cortex, which only completes
after birth, imply that it is only after birth, when the infant awakens and cortical development
completes, that pain will be experienced. To put that slightly differently, it is seemingly reasonable,
given the immature nature of the foetus and the apparent lack of wakeful activity, to reject the
possibility of foetal pain on the grounds of pain being objectively impossible in utero.

The meaning of biological immaturity

The conclusion that the foetus cannot experience pain at any stage of development has met with
considerable resistance.9,11 Opponents point out that the cortex might not be the only neural structure
capable of processing pain. Subcortical structures, such as the brainstem, for example, respond to
noxious stimulation. Subcortical responses occur in response to needling from 18 weeks GA.36 In
addition, anencephalic infants, who typically lack almost the entire cortex, demonstrate a capacity to
learn and show evidence of emotion12,37, which supports the possibility of some kind of brainstem-
mediated pain experience.11 An anencephalic foetus also withdraws from noxious stimulation,
demonstrating that withdrawal is mediated at a subcortical level.38 Infants with signiﬁcant neonatal
neurological injury due to a parenchymal brain injury also respond to noxious stimulation with
a pattern of biobehavioural and facial reactions similar to infants without brain injury.39
If the foetus is sedated and asleep in the womb then it might be possible to dispense with all
arguments based on neurobiology because it is typically assumed that a sleeping organism cannot feel.
Mellor et al. 28 propose that the foetus is unconscious based on the presence of powerful sedating


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chemicals in the womb (most notably adenosine), the presence of sleep-like EEG patterns observed in
the lamb foetus that enter a more quiescent state during stress, and a lack of movement during stress.
Unfortunately, these conditions do not guarantee or dictate a lack of wakefulness. Relaxation and sleep
can be broken by noxious stimuli40 and although the EEG activity in the lamb foetus enters a state of
relative quiescence during stress (such as caused by umbilical cord occlusion) there are clear indica-
tions of large spikes within that quiescence.31 Rather than EEG silence during stress, there is a shift
from one EEG pattern to another and we have no direct means of assessing what either pattern means
in terms of experience. It is also questionable whether the stress of umbilical cord occlusion is
comparable to the nociceptive stress that will occur during surgery.
A series of studies with rats have also demonstrated that mammalian foetal behaviour is complex
and organised. Foetal behaviour includes temporal rhythmicity, movement synchrony and motor
coordination that are related to postnatal grooming, suckling and locomotor behaviour.41–44 The rat
foetus responds vigorously to chemical stimulation, such as a lemon infusion, and preconditioning
with other chemical stimulation, such as mint, modifies these responses.45 Human foetuses also detect
and respond to chemical stimuli46, move away when approached with a scalpel or needle during
surgical procedures47 and show evidence of learning in utero.48,49 While these responses might occur
during a state of sleep or sedation they are certainly not incompatible with wakefulness.
Associating EEG patterns during gestation with sleep-like states is also difficult because there is, in
general, no clear cut-off between conscious and unconscious EEG activity.50,51 For the neonate, and
presumably the foetus, sleep is accompanied by ongoing background EEG without obvious differences
between wake and sleep.52,53 These observations of cortical activity during ‘sleep’ in the neonate raise
the question of what ‘sleep’ and ‘wakefulness’ actually mean for the neonate or foetus.
A subcortical response to noxious stimulation and lack of uncertainty regarding the nature of foetal
consciousness makes a definitive rejection of foetal pain difficult. The difficulty stems not just from a lack
of neuroscientific knowledge but also from a lack of substance with regard to the nature of sensory
experience. Without a satisfactory or comprehensive approach to the nature of sensory experience,
terms such as ‘awake’ or ‘conscious’ or ‘pain’ and so forth take on a somewhat arbitrary character and can
be attached to any apparently coherent neural behaviour. Certain patterns of EEG activity might or might
not be associated with being awake; certain neuronal activity might or might not be associated with
being conscious; and certain areas of the brain might or might not be necessary for pain. There is no
means of deciding these issues without an adequate account of the subjective terms in use.

Why the definition of pain is critical

How we define pain is critical. Defining pain as the response to noxious stimulation might seem
sensible until it is realised that such a definition will allow almost anything to be in pain because even
rocks respond to violent force by shattering and thermostats respond to high temperatures by
changing their internal state. Allowing rocks and thermostats to have a pain response is much too
permissive. Furthermore, a definition of pain based on response leads to a tautological understanding
of pain. Pain is defined in terms of a stimulus that is deemed to be painful because it elicits the pain
response. Put simply: pain is defined as pain.54,55
A definition of pain that includes the content of pain is required to avoid tautology. Definitions of
pain that avoid tautology usually include cognition, sensation and affective processes such as that
provided by the International Association for the Study of Pain (IASP).56 The IASP have defined pain as
‘‘an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or
described in terms of such damage. pain is always subjective. Each individual learns the application of
the word through experiences related to injury in early life.’’
By this definition, pain is no longer regarded as merely a physical sensation of noxious stimulus and
disease but is seen as a conscious experience which may be modulated by mental, emotional and
sensory mechanisms and includes both sensory and emotional components. The multidimensional
emphasis and reference to subjectivity makes it difficult to deny an active cortical role for pain
experience. Suppression of cortical activity is widely associated with profound loss of conscious
experience.57 For pain to be supported by subcortical structures, therefore, requires that pain be
redefined as something less than a multidimensional, subjective experience.


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Those that support the possibility of foetal pain have made attempts to change the IASP definition of
pain.58 Those efforts have largely focussed on removing the apparent requirement for language from
the definition and resulted in a new note being added to the IASP definition: ‘‘The inability to
communicate verbally does not negate the possibility that an individual is experiencing pain and is in
need of appropriate pain-relieving treatment.’’
The note clarifies that being unable to talk does not mean a person is unable to experience pain but
it does not change the substance of the IASP definition. It is unlikely that the efforts to change the IASP
definition were intended to clarify something as obvious as silence not delivering pain relief.
Presumably, the intention was to reduce the requirements for pain experience so that pain could be
more easily attributed to inherently, rather than temporarily, non-verbal beings such as the foetus.
Rather than something multidimensional and subjective, pain is reduced to a physical, raw nature by
stripping away the layers of conceptualisation that we associate with language. The challenge is to
understand pain as something apprehended rather than comprehended. Pain is something that just is,
an experience that is complete but irreducible and immediate: a pure immediacy that cannot be
allowed any durability.
Conceptual, language-ridden beings such as persons cannot experience sensation as a pure
immediacy. Sensory experiences in conceptual beings are propositional. Such beings are not merely in
pain but know that they are in pain. Knowing that I am in pain involves concepts – ‘sore’, ‘stabbing’,
‘damage’, ‘threat’ and ‘body’ – that are themselves rooted in general beliefs. For conceptual beings,
there is no such thing as a pure pain experience that can be extracted from those general beliefs. Every
painful experience will invoke its own set of autobiographical associations and expectations that form
both the content and the context of the pain experience.
Conceptual beings cannot return to a more innocent, aconceptual state. Perception in conceptual
beings is structured by concepts and categories from language and thought and is directed towards
what is recognised as threatening or desirable. The perceptual field no longer dictates behaviour or
experience because conceptual beings highlight the structurally relevant elements, keeping the correct
components together and the incorrect components apart. Perception demands a flow of interpreta-
tion that informs and constitutes the experience. Every experience that a conceptual being has will
follow and be dependent upon a period of conceptual development.
The foetus has no options regarding its behaviour in the presence of noxious stimuli. It cannot, for
example, decide it is in his/her best interests to remain still during surgery any more than he/she can
launch a protest against an abortion. The foetus must react according to the dictates of its biology in the
presence of an eliciting stimulus. Anything further will require a conceptual apparatus that will be
provided as language and higher forms of thought and behavioural organisation become possible
through development. The suggestion that the foetus can feel an equivalent pain to that of an older,
conceptual infant misses or denies the necessary role of development in constructing sensorial
experience. Nevertheless, the question remains, what is sensation before conceptual development?

Sensation before conceptual development

Insisting that only conceptual beings have the apparatus to engage in sensation means denying
sensation to all animals and all infants less than approximately 2–3 months of age. Such a position
strikes many as implausible.9,12,58,59 As discussed earlier in this article, one possible way to avoid the
conclusion that only human beings of a certain advanced age experience sensation is to define
sensation as something raw and pure. Animals and the foetus might have a perceptual sensitivity to
features of the environment that are entirely contained within nature. What exists in animals and the
foetus also exists in conceptual beings but perceptual sensitivity in conceptual beings is taken up into
the ambit of consciousness where raw immediacy becomes abstract experience.59
Even in non-verbal, aconceptual, creatures, however, there is more to perceptual sensitivity than
merely neural activity.60,61 The visual system endows objects, for example, with colour in the same
sense that cows endow grass with the character of food. Grass is food for cows because cows eat grass.
If cows did not eat grass then grass would not be food. The existence of grass as a food for cows depends
upon the relationship between cows and grass and that relationship cannot be reduced to a neural
event because the neural event is only one part of the story.


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Sensory perception might be viewed in the same way. Sensations are not projected into objects,
which cannot sense, but sensations arise through a relation with the object. That relationship makes
the appearance and existence of the object, as qualities of the object, possible. Colours, for example,
inhere in objects only by virtue of their relations with a being perceptually sensitive to colour. In similar
fashion, noxious stimuli are painful only by virtue of their contact with a being perceptually sensitive to
stimuli in the noxious range. The entire experience is more than just nervous tissue activity even
though the physiological or sensory structure of the perceptually sensitive being determines the
experienced content of the stimulus. This observation is important because it allows us to potentially
say that the foetus feels pain without forcing us to also say that rocks and thermostats feel pain.
For the foetus, an existence of ‘pain’ rests upon the existence of a stimulus that poses a threat to
tissue, being detected by a nervous system capable of preferentially responding to stimuli that pose
a threat to tissue. The entire experience is completely bounded by the limits of the sensory system and
the relationship between that system and the stimulus. If pain is conceived of in this manner then it
becomes possible to talk of foetal pain anytime between 10 and 17 weeks GA when nociceptors
develop and mature, and there is evidence of behavioural responses to touch.35 Further developments
of the nervous system then provide for alterations or elaborations of the pain response; each
development potentially provides what some have called an experience of pain relevant to that stage
of development.9,58

Conclusions

Decisions regarding foetal pain are typically resolved by reference to neuroanatomy. Before the
presence of a system capable of detecting noxious events, it is reasonable to deny the possibility of pain
in utero. Deciding the minimally necessary neuroanatomy, however, is not straightforward. There is
considerable disagreement regarding the contribution of the cortex and the possibility of pain, and
other conscious experiences, being supported subcortically. One reason for this disagreement is the
lack of precision in defining what is meant by ‘pain’. If pain is defined in terms of a noxious stimulus
being detected by a nervous system that can preferentially respond to stimuli in the noxious range then
pain can be attributed to the foetus from around 10 weeks GA. However, if pain is defined as an
elaborate multidimensional experience that is subjective, then pain can never be attributed to the
foetus because it is implausible to attribute that much conceptual activity to the foetus.61
This review is agnostic with regard to which view of pain is ‘correct’. It is possible that both views are
correct or both views are incorrect but it is not possible that both views are equivalent. Pain in
a conceptual being is both apprehended and comprehended whereas pain in a non-conceptual being is,
at most, only apprehended. Once pain is comprehended, there is no return to a more innocent state of
apprehension. Sensory experience for conceptual beings is not the product of raw experiences stacked
together but is a profoundly different way of experiencing the world. Pain for the foetus, whatever that
might feel like, will be bounded by the activity in dedicated neural pathways set in motion by a stimulus
in the noxious range. The foetus just is, and his experiences just are, and they just are without further
regard. Pain for the conceptual infant, in contrast, will open out into the unfolding of his or her life to be
connected with a vast array of other sensations, emotions and understanding of the world and the self.
The conceptual being has a self-existence that has great regard towards all experience.

Practice points

There are numerous surgical procedures, in addition to surgical abortion, that may induce
foetal pain but that remains uncertain.
The uncertainty regarding foetal pain means that any direction to change clinical practice
based on foetal pain would be premature.
The use of analgesia or anaesthetic during in utero procedures should remain at the discretion
of the medical team responsible for the procedures.

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8 S.W.G. Derbyshire / Best Practice Research Clinical Obstetrics and Gynaecology xxx (2010) 1–9

Research agenda

Clinical trials evaluating the clinical benefit of analgesia or anaesthesia during in utero
procedures.
Neural development in utero.
Psychological investigations of sentient versus propositional sensory experience.

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