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Fetal pain is a subject of intense political and academic debate as part of the controversy over abortion. Determining the stage of pregnancy at which a fetus is able to feel pain could have a significant effect on abortion laws and practices.

Many scientists believe that a fetus is able to feel pain sometime during the pregnancy usually after 26 weeks gestation although the question of exactly when pain might be possible is disputed. Some academics argue that it appears as early as seven weeks after conception. Others claim that pain cannot be felt until the third trimester of pregnancy or until after birth.

Multiple nerve systems are involved in the sensation of pain. When the brain and nervous system are fully developed, the sensation is triggered by nociceptors reacting to some stimulus. The resulting signal travels via the peripheral nervous system to nociceptors associated with the spinal column. It then travels up the spinal column to the thalamus, and onward to the cerebral cortex, where it is finally interpreted as a painful sensation. Early in development, from about 12-18 weeks gestation, there is a complete link from the periphery to the thalamus in the brain and the fetus shows clear evidence of defensive reactions against tissue damage including hormonal and hemodynamic responses. After about 26 weeks gestation there is a complete link from the thalamus to the cortex of the brain. Cortical responses in premature babies of about 25 weeks gestation have been recorded during the usual heel lance procedure performed shortly after birth. In summary, there is good evidence that from about 26 weeks gestation the fetal brain can be considered a functional unit capable of processing noxious sensory input.

Several recent reviews have reached quite different conclusions as to whether this system is necessary and sufficient for pain experience in the fetus. Lee and colleagues, in their JAMA review, suggested that a cortical response can be equated with a painful experience. Derbyshire, however, argued that painful experience cannot be directly coded into the cortex because it is a subjective experience that is dependent upon developmental events that happen outside of the womb.

Medical opinions

A 1988 study observed changes in heart rates and hormonal levels of newborn infants after circumcision, blood tests, and surgery — effects which were alleviated with the administration of anesthesia.

In 1997, Dr. Robert White, director of the Division of Neurosurgery and Brain Research Laboratory at Case Western Reserve School of Medicine and a member of the Vatican's Pontifical Academy of Sciences , gave testimony before the House Constitution Subcommittee of the Congress of the United States. He stated that, at 20 weeks' gestation, the fetus "is fully capable of experiencing pain...Without question, all of this is a dreadfully painful experience for any infant subjected to such a surgical procedure."

His assertions were supported by Dr. Paul Ranalli, a neurologist at the University of Toronto, who has cited several observations to support the belief that a fetus can experience pain. These include observing a fetus "withdraw from painful stimulation", and the fact that stress hormones detected in adults observing pain has also been found in the blood samples of aborted fetuses. Dr. Paul Ranalli is a member on the Advisory Board of the deVeber Institute for Bioethics and Social Research, a pro-life organization.

In 2001, a working group appointed by the Royal College of Obstetricians and Gynecologists in the United Kingdom contradicted these findings, stating that "little sensory input" reaches the brain of the developing fetus before 26 weeks. "Therefore reactions to noxious stimuli cannot be interpreted as feeling or perceiving pain."

In 2005, Mellor and colleagues reviewed several lines of evidence that suggested a fetus does not awake during it's time in the womb. If the fetus is asleep throughout gestation then the possibility of fetal pain is greatly minimised.

Later in 2005, a meta-analysis of existing experiments undertaken by the Journal of the American Medical Association concluded that the lack of functioning neurological pathways to a fetus' cererbral cortex before 26 weeks meant that it could not experience pain before then. The meta-study was criticised by pro-life groups who were suspicious of the prior involvement of several authors of the report. One directs an abortion clinic at San Francisco Hospital, while the lead author undertook legal work with NARAL Pro-Choice America for six months.

In 2006, a clinical review published in the British Medical Journal concluded that pain is dependent upon cognitive and emotional developments that occur after birth:

"Theories of development assume that the early human mind begins with minimal content and gradually evolves into the rich experience of older children and adults. Although the view of a neonate as a blank slate, or tabula rasa, is generally rejected, it is broadly accepted that psychological processes have content concerning people, objects, and symbols, which lay in the first instance outside the brain. If pain also depends on content derived from outside the brain, then fetal pain cannot be possible, regardless of neural development".

References

1. ^ Robinson, B.A. (2006). Can a fetus feel pain?. Ontario Consultants for Religious Tolerance. Retrieved December 14, 2005.
2. Anand, K., Phil, D., & Hickey, P.R. (1987). Pain and its effects on the human neonate and fetus. New England Journal of Medicine, 316 (21), 1321-9. Retrieved 2006-01-11 from The Circumcision Reference Library.
3. The deVeber Institute for Bioethics and Social Research. (2004). Perspectives 2004. Retrieved December 23, 2006.
4. Mellor D.J., Diesch T.J., Gunn A.J., & Bennet L. (2005). The importance of ‘awareness’ for understanding fetal pain. Brain Research Reviews, 49(3), 455-71. Retrieved December 23, 2006.
5. Lee, Susan J., Ralston, Henry J. Peter, Drey, Eleanor A., Partridge, John Colin, & Rosen, Mark A. (2005). Fetal Pain: A Systematic Multidisciplinary Review of the Evidence. Journal of the American Medical Association, 294 (8), 947-954. Retrieved December 23, 2006.
6. Derbyshire, S.W.G. (2006). Can fetuses feel pain?. British Medical Journal, 332 (7546), 909-12. Retrieved December 23, 2006.

External links

• Pro-life site presenting case for fetal pain from second month of pregnancy: HTML version.
• A review of clinical evidence concerning fetal pain, JAMA. 2005;294:947-954. HTML version
• 109th Congress, U.S.A. "Unborn Child Pain Awareness Act of 2005." 1st Session, S.51. (January, 2005). PDF version, HTML version
• National Right to Life Committee's webpage of testimonies regarding fetal pain. HTML version

• Abortion