Unborn child can feel pain at 20 weeks, say researchers

Unborn child can feel pain at 20 weeks, say researchers

El Sydney Morning Harald de hoy publica esta noticia que toma del DTelegraph. ¿Qué opinas?


The unborn child may be able to feel pain as early as 20 weeks into pregnancy, a finding that suggests pain relief should be considered for the 2,500 extremely premature babies born each year who may be subjected to painful procedures.

The head of a British government-appointed group of experts said a foetus was definitely aware of pain by 24 weeks, perhaps as early as 20 weeks, according to a review of the latest research.

The Medical Research Council’s expert group, chaired by Prof Eve Johnstone of Edinburgh University, makes a strong case for additional research on ways to prevent the unnecessary suffering of extremely premature children.

Prof Johnstone said these babies had to undergo painful procedures, such as heel pricks, blood monitoring, injections and insertion of breathing tubes. “We ought to study this carefully.”

Premature babies are already known to have a higher incidence of problems in later life. There was also, said the report, evidence that “multiple painful procedures experienced by pre-term neonates may affect their pain-related behaviours later in life”.

But the use of pain relief for premature babies was not straightforward because analgesics might interfere with long-term development. “Intervention with opioids might have deleterious effects on development, which had a bearing on adult behaviour,” said the report.

Morphine is still the primary drug for pain relief and concerns include whether this could trigger addictive behaviour in later life.

The report will also raise questions about why, when many women opt for pain relief during birth, the foetus is not also given analgesia. Prof Johnstone said it was unlikely a normal physiological process would have long-term damaging consequences.

“Most babies grow up normal and they don’t have the problems that these premature babies do,” she said.

The issue of foetal pain has been highly controversial. Some claim that it is merely a pretext used by pro-life organisations to attack the use of abortions. Others believe that more thought has been given to preventing the suffering of laboratory animals than to the suffering of the unborn child.

The 20-week theoretical limit suggested by the MRC group is significantly earlier than the 26-week pain limit laid down four years ago by the Royal College of Obstetricians and Gynaecologists.

This would seem to suggest that a foetus could suffer because there are no guidelines for the use of pain relief in abortions between 20 weeks and 24 weeks – the legal abortion limit.

But one of the working party, Prof Bill Dunlop of the University of Newcastle, pointed out that late legal abortions, which are rare, were usually conducted by inducing labour.

The report focused on two key issues: when the developing nervous system of a foetus is capable of responding to damage and when its brain is aware of sensations such as pain.

In 1997, the Royal College of Obstetricians and Gynaecologists concluded that the foetus was not “aware” before 26 weeks because nerve connections between areas of the developing brain, the cortex and the thalamus, are not completely developed until then.

The connections are crucial for pain perception because the thalamus is the reception area for most of the sensory input to the brain travelling up the spinal cord; and the cerebral cortex is associated with thought, consciousness, emotion and so on.

But consciousness is a highly contentious subject, even lacking a universally accepted definition.

Although most terminations are before 13 weeks, when a broad sweep of medical opinion agrees a foetus cannot feel pain, concerns about the 26-week limit have been expressed, notably in a Daily Telegraph survey of neuroscientists last year. The majority of respondents felt pain relief should be given to the foetus in abortions between 11 and 24 weeks. Research by one member of the expert group, Prof Vivette Glover of Queen Charlotte’s and Chelsea Hospital, raises the possibility that the foetus feels something after 17 weeks.

The new report by the MRC working group attacks the idea that pain perception suddenly switches on in the foetus, or is due to activity in a particular brain area. Pain perception requires interactions among highly interdependent brain areas. “Such function will not ‘switch’ on at a particular stage of fetal life… It will mature over many pre- and post-natal months to produce complete pain awareness,” said the report.

The report says connections to the cortex begin to develop at about 20 weeks’ gestation, suggesting that this is the earliest stage of gestation at which pain can be perceived.

The Telegraph, London


Unborn child can feel pain at 20 weeks, say researchers
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