New Report Says a Fetus Can't Feel Pain Before 24 Weeks

80beatsBy Joseph CalamiaJun 26, 2010 1:05 AM


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In a development that's certain to stir passions in the abortion debate, the Royal College of Obstetricians and Gynaecologists in the UK published a report today on "fetal awareness." The group states, citing a review of current research, that human fetuses cannot feel pain before 24 weeks. The group's reasoning, as described in a press release, is based on these points:

-The fetus cannot feel pain before 24 weeks because the connections in the fetal brain are not fully formed -The fetus, while in the chemical environment of the womb, is in a state of induced sleep and is unconscious -Because the 24 week-old fetus has no awareness nor can it feel pain, the use of analgesia is of no benefit -More research is needed into the short and long-term effects of the use of fetal analgesia post-24 weeks [Royal College of Obstetricians and Gynaecologists]

This is certainly not the first debate over whether a fetus can feel pain. Fetal surgeries have led doctors to ask this question, as they determined whether anesthesia was appropriate and at what stage in development. As summarized in a 2008 New York Times Magazine article, researchers have looked at fetal flinch responses, heart rate, and levels of stress hormones. But any metric has remained controversial. Take stress hormones, for example. Do you say that any fetus that can release these hormones feels pain? Or do you wait until it develops the nervous system to register those hormones? Or do you say that an undeveloped nervous system makes the fetus more susceptible to pain, since it hasn't developed the system to suppress it? In April, Kanwaljeet Anand, director of the Pain Neurobiology Laboratory at the University of Tennessee Health Science Center in Memphis and an often-quoted researcher in the debate, described some of the issues:

When a fetus of that age [18 to 20 weeks] gets a blood transfusion, for example, changes in heart rate and blood pressure accompany shifts in circulation and spikes in stress hormones. A morphine-like drug calms all of those responses down. "The die-hards will say these are all reflexes," Anand said. But new evidence, he argued, suggests that the very young brain is developed enough in the right places to take in those sensations and translate them into pain. [Discovery News]

The Royal College of Obstetricians and Gynaecologists' report differs from Anand's assessment, and argues that fetuses younger than 24 weeks don't have the brain connections to register pain, and if they could register the chemical signals, they couldn't make out what they mean.

The report on pain perception says: "It was apparent that connections from the periphery to the cortex are not intact before 24 weeks of gestation and, as most neuroscientists believe that the cortex is necessary for pain perception, it can be concluded that the foetus cannot experience pain in any sense prior to this gestation." Even after 24 weeks, "it is difficult to say that the foetus experiences pain because this, like all other experiences, develops post-natally along with memory and other learned behaviours". [The Gaurdian]

Understanding when a fetus can feel pain has implications for abortion laws, and groups on both side of the debate have weighed in on today's reports. As the BBC reports, those in the United Kingdom question the reports' implications for the 1967 Abortion Act, which covers all parts of the UK apart from Northern Ireland, and caps legal abortion at 24 weeks (with some exceptions, regarding dangers to the life of the pregnant woman or evidence of serious fetal abnormality). Some activists had campaigned to reduce that timeframe, but UK government representatives have said that there are currently no plans to change the act.

A Downing Street spokeswoman said: "The Prime Minister's view is that he will be led by the science." She added: "At the moment there are no plans to change the policy." [BBC]

Related content: DISCOVER: When Does a Fetus Feel Pain? 80beats:Sex-Selective Abortions in China Have Produced 32 Million Extra Boys 80beats: Obama to Rescind “Conscience” Rule on Abortion and Birth Control 80beats: Federal Rule Lets Doctors Deny Medical Care Based on Religious Concerns 80beats: Leftover Embryos at Fertility Clinics Pose Troubling Questions for Patients Image: flickr / Chris Denbow

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