[Paleopsych] Stuff (NZ): Babies are not conscious in the womb
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Wed Apr 13 18:10:48 UTC 2005
Babies are not conscious in the womb
22 February 2005
By KENT ATKINSON
Babies - both human and animal - react to touch, sound, and other
external stimuli in the womb, but do not consciously experience them,
says a group researching animal welfare.
Professor David Mellor, of Massey University, said yesterday that the
embryo and foetus are apparently never conscious, and actually spend
much of their time anaethetised.
"Consciousness first appears only after birth, associated with first
exposure to air, gravity, hard surfaces, unlimited space and, usually,
to cold ambient conditions," he said.
Prof Mellor, director of the university's animal welfare science and
bioethics centre, said he had made a fresh evaluation of consciousness
in the womb - particularly in terms of sheep - after meatworkers at a
slaughter plant expressed concern that foetuses of slaughtered animals
might be drowning in their amniotic fluid.
He said the study used extensive research into sheep which had been
originally intended not for animal welfare purposes, but because sheep
were an excellent large-animal "model" for humans. A collaboration with
Auckland University's foetal physiology and neuroscience group had
produced insights relevant to human foetuses.
Prof Mellor will present a major paper to a two-day London conference on
animal sentience, starting on March 17, which will examine the ability
of a foetus and newborn to receive sensory information and to "feel"
sensations that cause suffering.
His paper will argue that the embryo and foetus cannot suffer before or
during birth, and that suffering can only occur in the newborn when the
onset of breathing sufficiently oxygenates its tissues sufficiently.
Prof Mellor said that many paediatricians were convinced that a foetus
in the womb could feel pain, because they based their judgement on
comparable premature infants born as early as 24 week to 28 weeks.
Those infants did experience pain, and paediatricians had assumed that
so did an age-equivalent foetus.
"But the chemical environment in the brain is very different after the
baby is born," he said. Breathing oxygen was a key difference, in
addition to loss of the chemicals produced by the placenta.
When a baby was born, breathing oxygen caused a critical chemical
messenger, adenosine, to be cleared from the bloodstream in seconds,
allowing it to start experiencing consciousness.
This indicated that stillborn babies that did not breath did not suffer
pain or distress - they simply went from being asleep in the womb to
profound unconsciousness and death.
Prof Mellor said future areas of research would look at differences
between foetuses that went through a normal birth and those that were
delivered by caesarian section.
Early indications were that providing the foetus could breath
sufficiently well to oxygenate its blood, the loss of placental
adenosine, the stimulation of cold air, loss of buoyancy, and
"mechanical" touch would mean a baby from a caesarian birth would not be
different to one which had gone through a normal delivery.
Prof Mellor said he expected the work with Auckland University to spur
In terms of humans, there was no doubt that doubt that babies before
birth reacted to a range of stimuli because the sense organs of foetuses
in the uterus began to work well before birth, he said.
Touch, sound and other stimuli affected the foetus, and could cause it
to move in the womb.
"But the evidence, accumulated over the last 25-35 years, is that this
does not occur at the conscious level," he said. Babies born with no
cerebral cortex - the part of the brain essential for consciousness -
could also respond with movements and hormone release and heart rate
But Prof Mellor said that though effects from stimulation of touch,
sight, sound, and taste were not at a conscious level," it is possible -
and some evidence suggests that it is in fact likely - that such effects
persist well beyond birth".
"Some might very well be at least benign, and perhaps even positively
advantageous, depending on what they are," he said. "Playing music and
speaking softly could well have beneficial effects".
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