21 April 2006

Fetuses cannot feel pain, says expert

In a review of evidence for the existence of fetal pain for the BMJ, Dr Stuart Derbyshire said that telling women who are considering abortions that fetuses could feel pain was inaccurate and exposed them to inappropriate medical treatment.

Dr Derbyshire found that while the necessary biological system required for pain is complete at 26 weeks’ gestation, real sensations of pain depend on experiences outside the womb.

Dr Derbyshire compared the pain response of an unborn baby to that of a fruit fly larva that reacts to a flame by bending and rolling away, describing it as merely an automatic biological mechanism designed to avoid harmful stimuli. Writing in the British Medical Journal (BMJ), he said: ‘The neural circuitry for pain in fetuses is immature. Pain becomes possible because of a psychological development that begins at birth when the baby is separated from the protected atmosphere of the womb and is stimulated into wakeful activity. It is something that comes from our experiences and develops due to stimulation and human interaction. Proposals to inform women seeking abortions of the potential for pain in fetuses are not supported by evidence. Legal or clinical mandates for interventions to prevent such pain are scientifically unsound and may expose women to inappropriate interventions, risks and distress.’

Dr Derbyshire described human pain as analogous to an alarm system, with nerve endings in the skin activated by harmful stimuli similar to triggers that set of alarms. The spinal cord is like the electrical wiring between a trigger and the alarm. It has been suggested that the minimum level of anatomical development for pain is the completion of the ‘spinothalamic’ muscular link from the spine to the thalamus, the part of the brain that processes information from the senses, at 23-25 weeks.

A study published in April from University College London revealed that scans on premature babies from 24 weeks having blood tests showed surges of blood and oxygen in sensory areas of their brains - suggesting pain was being processed. This claim has been disputed by Dr Derbyshire on the website spiked. (See So, can a fetus feel pain?) The US government is considering laws that would force doctors to tell women seeking an abortion that there is ‘substantial evidence that the process of being killed in an abortion will cause the unborn child pain’. Doctors who carried out abortions after 22 weeks without painkilling drugs would be fined $100,000 (£57,700) and lose their medical licence.

Dr Derbyshire said whether or not fetuses felt pain did not affect the abortion debate because it did not change the moral viewpoints of the pro-choice and pro-life lobby, or the legality of terminations. But he said: ‘Avoiding a discussion of fetal pain with women requesting abortions is not misguided paternalism but a sound policy based on good evidence that fetuses cannot experience pain.’ And he said giving fetuses painkilling drugs - which would have to be given through the placenta - involved procedures which may expose the woman to unnecessary risks and distress.

Anna Pringle, a spokeswoman for the pro-life charity Life, said: ‘This complex debate has been ongoing for a long time. ‘Of course, if the unborn child can feel pain - as has been suggested by other research - then it makes abortion all the more horrifying. What we know for certain is that by the age of 20 weeks unborn children can respond to external aural stimuli such as music and conversation, and the 4-D ultrasound techniques used by Professor Stuart Campbell have shown that a child also responds to physical stimuli.’ But she agreed that the issue of whether fetuses felt pain was irrelevant to the abortion debate. ‘A human person is a human person, and as such has the right to life, which is quite literally fundamental to all other rights.’

See:

Stuart Derbyshire. Can fetuses feel pain?, BMJ 2006 Apr 15;332:909-912

Pain cannot be felt by a fetus, says psychologist, Daily Telegraph, 14 April 2006

Fetuses ‘cannot experience pain’ , BBC, 13 April 2006