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WHEN DOES A FETUS FEEL PAIN?

Jan 17, 2006

In Arkansas and Georgia, doctors are required to tell women seeking abortions that the fetus will experience hurting during the procedure. Then they must offer anesthesia. Other states are because similar legislation and Congress may soon vote on the Unborn Child Pain and Awareness Act, which would require abortion providers in the US to read a argument to women seeking an abortion that a fetus older than 20 weeks "has the concrete structures necessary to feel pain."

Is that assertion truthful? Doctors readily agree that a fetus at 20 weeks and even earlier will pull abroad from a pin prick or other "noxious stimulus." They exercise non agree, however, that the reaction indicates the fetus is experiencing pain.

According to a study published terminal summertime in the Journal of the American Medical Association (JAMA), a fetus is not capable of experiencing pain until 28 to 30 weeks later conception, when the nerves that carry painful stimuli to the brain take developed. Before that, the fetal reaction to a baneful stimulus is a reflex that does not involve consciousness, they write (JAMA 2005; 294:947-954).

That is why the authors of that written report oppose any law that would require doctors to tell women that a fetus can experience hurting earlier than 28 weeks.

"Because pain perception probably does not role before the third trimester, discussions of fetal pain for abortions performed before the stop of the second trimester should be noncompulsory," the authors country. "Fetal anesthesia or analgesia should not be recommended or routinely offered for abortion because current experimental techniques provide unknown fetal do good and may increment risks for the woman."

Reflex responses to noxious stimuli occur early in development, (A) before thalamocortical circuits are functional; noxious stimuli trigger reflex movement without cortical involvement. Activated by a noxious stimulus (1), a peripheral sensory neuron (two) synapses on a dorsal horn interneuron (3) that in plough synapses on a ventral horn motor neuron (4), leading to reflex muscle contraction and limb withdrawal (five).Later in development, (B) noxious stimuli (1) activate peripheral sensory neurons (two) that synapse on spinothalamic tract neurons (3), the axons of which extend up the spinal cord as the spinothalamic tract (4) to synapse on neurons of the thalamus (5). From here, thalamocortical axons synapse on cortical neurons, resulting in the conscious perception of pain.

LACK OF CONSENSUS: 'POOR PUBLIC POLICY'

Arthur Caplan, PhD, Manager of the Center for Bioethics, and Chair of the Department of Medical Ethics at the University of Pennsylvania, echoed that determination in his testimony on Nov one before a congressional subcommittee examining "pain of the unborn."

Dr. Caplan argued that because there is no consensus in the scientific customs virtually when a fetus tin can feel pain, a law requiring doctors to claim that a fetus experiences pain from 20 weeks on "would not merely be poor public policy, it would set a terrible precedent for other topics where Congress might choose to mandate disclosures most 'facts' for political or even ethical reasons which accept no foundation in scientific discipline or medicine."

Only as with other scientific matters that involve reproductive technologies – and enquiry – the issue of when the fetus feels pain has go highly politicized. The JAMA paper was criticized past the National Right to Life Commission, which issued a news release that pointed out that the lead author of the study, Susan J. Lee, was previously a lawyer for NARAL, which supports the correct to abortion, while another author, Eleanor A. Drey, MD, is the Director of an abortion clinic in San Francisco. Ms. Lee is currently a medical educatee at the Academy of California-San Francisco.

Paper IS BALANCED AND PEER-REVIEWED

But that does not discredit the findings, according to Michael A. Williams, MD, Chair of the AAN Ethics, Law and Humanities Committee and Professor of Neurology at Johns Hopkins Medical School. "JAMA is a peer-reviewed publication, which means the article was sent out to other experts who know the science and the ethics," he said. "If at that place had been anything false or far out in this paper, it would have been caught. Then it has withstood the peer review procedure for a scientific paper, and I call back we should accept it every bit a peer-reviewed publication. I remember it is a balanced paper."

Dr. Williams contends the proposed legislation is inappropriate considering it requires physicians to brand statements that are not supported by scientific evidence. "In the absence of pain pathways, there's not good anatomical or physiological evidence that a fetus at 22 weeks feels pain," said Dr. Williams. "Notwithstanding, that's the premise behind legislation."

Dr. Kanwaljeet Due south. Anand disagrees with the conclusions of the JAMA paper, explaining that the authors "represent hurting every bit a hard-wired system, but it is not a hard-wired system. Its non like a computer switch. The nervous organisation does non develop that way."

The JAMA authors examined more than 2,000 articles for information about fetal pain prior to thirty weeks gestational age. The authors defined pain as the sensation of noxious stimuli, which requires the participation of the "thalamocortical circuitry" of the brain. That pathway, they conclude, does not develop until at least 28 weeks after formulation.

"To the best of our agreement of how the experience of pain is processed, the young fetus doesn't take the neural network, the architecture, to experience pain," said Mark A. Rosen, Medico, Professor and Vice Chair of the Section of Obstetrics, Gynecology and Reproductive Sciences and Manager of Perinatal Medicine and Genetics at the University of California-San Francisco, one of the authors of the paper. "Therefore, information technology seems unlikely that what we consider pain is experienced by the fetus."

FETAL Pain EXPERT DISAGREES WITH Report

Ane expert on fetal hurting, all the same, disagrees. Kanwaljeet S. Anand, Md, Professor of Pediatrics, Anesthesiology, Pharmacology, and Neurobiology at the University of Arkansas, asserts the human fetus can experience pain from at least twenty weeks after conception. The "gate theory" of hurting first proposed in 1965 by psychologist Ronald Melzack and anatomist Patrick Wall, he contends, demonstrates that pain signals on their way to the brain produce the perception of pain even before they reach the cerebral cortex (Science 1965; 150:971–979).

The authors of the JAMA paper, Dr. Anand said, "represent pain as a difficult-wired organisation, but information technology is not a hard-wired arrangement. It'south not like a reckoner switch. The nervous organization does not develop that way."

Neonatal pain structures are non the same as those in an adult, Dr. Anand said. The a-beta fibers, for example, which provide proprioception in the adult, are not involved in adult pain processing.

"Nonetheless, in the neonate and fetus they seem to perform that additional function," Dr. Anand said. "The structures and mechanisms used for pain processing in early life are unique to each stage of development. 1 cannot say that because the structures used for pain perception in adults are underdeveloped in the fetus, hurting perception is non nowadays."

In addition, the perception of pain requires more the participation of the somatosensory cortex in the brain, Dr. Anand contends.

"If yous ablate the somatosensory cortex, that does not take away pain," he said. "And if you stimulate the somatosensory cortex, that does not cause hurting. On the other manus, if you ablate certain thalamic nuclei, pain goes abroad, and if you stimulate places in the thalamus, pain is perceived. Sensory processing in the thalamus develops well before the somatosensory cortex."

Dr. Michael A. Williams: "If at that place had been annihilation false or far out in this newspaper, it would have been caught. And so information technology has withstood the peer review process for a scientific newspaper, and I think we should accept it equally a peer-reviewed publication. I think it is a balanced paper."

REVIEW IS INCOMPLETE, EXPERT CONTENDS

The authors of the JAMA article, he said, ignore the fact that hurting processing also occurs at the thalamic level. He noted that in their survey of the literature, the authors did not include manufactures that make such a claim.

"A systematic review should exist reproducible, but I couldn't replicate the search they had done," Dr. Anand said. "Obviously, this is not a systematic review. They've ignored relevant evidence for fetal sensory processing, memory, and learning in utero, which implies witting perception. I retrieve there is concern that the authors have a certain bias because they did not follow the standard methodology for systematic reviews."

Dr. Anand, who submitted testimony on fetal hurting to the U.s.a. Section of Justice in 2004 regarding the ban on partial-nativity abortions, said he is not morally opposed to abortion.

"I have no opinion in that matter," he said. "I'g not pro-life; I'm not pro-pick. I'm just a state doctor. I don't belong to any organizations that promote or block abortion."

His testimony, however, has often been cited by those who support a ban on partial-nascence abortion.

Although Dr. Rosen does non believe that the fetus before 28 to xxx weeks can feel what we consider pain, he agrees with Dr. Anand that a fetus even before that stage can be harmed by "noxious stimuli." A needle prick or an incision tin can set off a stress response that results in an increase in blood pressure, heart rate, and stress hormones, Dr. Rosen said. The stress reaction of the fetus before 28 weeks may be a reflex comparable to an adult pulling his hand from a flame even before feeling hurting, only this reflex all the same can take harmful furnishings.

"There'southward plenty of reason to hypnotize a fetus for surgical procedures that have cypher practise with the experience of pain," Dr. Rosen said. "The goal is to block the stress response, which tin be detrimental, and a fetus can take a stress response without experiencing pain."

POLITICIZING FETAL PAIN

Dr. Rosen also agrees with Dr. Anand that the question of fetal pain has been highly politicized. "The scientific question about the capacity to experience pain is clearly an contained question from the event of the right to ballgame or anything to practice with ballgame," Dr. Rosen said.

Dr. Anand, nonetheless, believes abortion forces doctors to face the possibility that the fetus may experience pain.

"First and foremost, I experience that nosotros must come from position of compassion," Dr. Anand said. "That compassion too applies to fetuses undergoing an abortion. I can't give a prescription of what should or should not be washed when a woman comes in for abortion, just my bias would exist to give the fetus the benefit of the doubt regarding the likelihood of pain perception."

Commodity IN Cursory

• ✓ Several months after the publication of a paper in JAMA that asserts that fetuses cannot feel pain before 28 to 30 weeks, there is controversy about its conclusions and political ramifications for setting policy on abortion.

REFERENCE

• Lee SJ, Ralson HJP, Rosen MA, et al. Fetal pain: a systematic multidisciplinary review of the evidence. JAMA 2005;294:947–954.

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Source: https://journals.lww.com/neurotodayonline/Fulltext/2006/01170/WHEN_DOES_A_FETUS_FEEL_PAIN_.3.aspx

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