Prenatal perception

Neonatal perception is the study of the extent of somatosensory and other perceptual systems during pregnancy. In practical terms, this means the study of fetuses; none of the accepted indicators of perception are present in embryos.

Recent studies have confirmed that fetuses feel pain and experience emotional responses at least as early as 14 weeks, when amniocentesis is preformed (Chamberlin, 1998, www.birthpsychology.com; Randalli, 2005, www.actionforlife.org.; Stanojevic, 2005, p.772). Anger and pleasure seemed to be the most obvious emotional responses. During a fetal blood transfusion, a “590% rise in beta endorphin and a 183% rise in cortosol have been documented in the fetus” (Randalli, 2005, www.actionforlife.org). These extremely high levels of hormonal secretions indicate a stimulus response to pain. Neurologist Dr Randalli (2005) explains that the pain a child feels between 20 and 30 weeks gestation may be more severe that one can imagine; “the fetus has a high density of pain receptors per square inch” at this gestational stage (www.actionforlife.org).

	According to Chamberlin (1998), emotional responses have also been observed during amniocentesis; fetuses will respond to the needle by shying away from it or kicking at it (www.birthpsychology.com).  The variety of responses of fetuses of the same age indicate that these are “not instinctual, but responses of fear, curiosity, and aggression” (www.birthpsychology.com).  During and immediately following amniocentesis, fetuses will experience fluctuations of heart rate. Heart rate and breathing motions may not stabilize for days (Chamberlin, 1998, www.birthpsychology.com). 

In their 4D-US study, Kurjak et al. (2005) observed a hormonal pleasure response to thumb-sucking at 14 weeks; indicating that an array of emotional responses are present even in the beginning stages of human development. Traumatic events in the neonatal intensive care unit confirm that the memory of a preterm infant is imprinted and this fear is intruded on adult life. Chamberlin (1998) discusses a baby named Edward who was born prematurely at 29 weeks gestation (www.birthpsychology.com). In the NICU, his delicate skin was torn off several times, accidently, as nurses removed adhesive tape. He learned to fear the sight and sound of adhesive tape which continued into adulthood. Feldman (2008) confirms this possibility in his discussion of the cognitive development of the memory of infants (p. 161-163). He discusses the hypothesis that the memory does indeed exist, but the inability to express verbal language inhibits the communication of the memory until around the age of three (Feldman, 2008, p. 161-163).

Medical studies and reviews

The hypothesis that human fetuses are capable of perceiving pain has not received sufficient evidence to be proven or disproven; the developmental stage of research and instrumentation is so far insufficient to this task. The issue is considerably complicated by the usual difficulties in perceptual research of unresponsive subjects: "Though techniques such as positron electron tomography scanning might reveal those parts of the brain that respond to a painful stimulus, this does not tell us what the individual is experiencing."

The accepted hypothesis of the means by which pain is perceived states that it requires certain physical structures and operations. These are not formed in fetuses until 20 weeks or more. The general consensus of the scientific community at this time is that only fetuses of this age or older are capable of perceiving pain.

Researchers from the University of California, San Francisco in the Journal of the American Medical Association concluded in a meta-analysis of data from dozens of medical reports and studies that fetuses are unlikely to feel pain until the third trimester of pregnancy. There is an emerging consensus among developmental neurobiologists that the establishment of thalamocortical connections (at about 26 weeks) is a critical event with regard to fetal perception of pain. Because pain can involve sensory, emotional and cognitive factors, it may be "impossible to know" when painful experiences are perceived, even if it is known when thalamocortical connections are established.

Electroencephalography suggests the capacity for functional pain perception in premature infants probably does not exist before 29 or 30 weeks; this study asserted that withdrawal reflexes and changes in heart rates and hormone levels in response to invasive procedures are reflexes that do not indicate fetal pain.

Also in 2005, Mellor and colleagues reviewed several lines of evidence that suggested a fetus does not awaken during its time in the womb. If the fetus is asleep throughout gestation then the possibility of fetal pain is greatly minimized.

There is also discussion among researchers about how pain is perceived over-all. Some researchers believe that because pain can involve sensory, emotional and cognitive factors, pain may not be sensed until after birth.

In 2001, a working group of the Medical Research Council (UK) in the United Kingdom called for more research regarding fetal pain. According to the Daily Telegraph, Eve Johnstone, the chair of that working group "makes a strong case for additional research." Ms. Johnstone told the newspaper, "We ought to study this carefully."

Though many researchers in the area of fetal development agree a fetus is unlikely to feel pain until after the seventh month of pregnancy, developmental neurobiologists suspect that the establishment of thalamocortical connections (at about 26 weeks) may be critical to fetal perception of pain.

Fetal pain and abortion

Scientific research has not come to definitive conclusions about the existence of fetal pain. In line with this, the ability of a fetus to perceive pain is not a major legal issue in the debate about abortion. It has not been a deciding factor in any US Supreme Court decision, including the 1973 Roe v. Wade. However, the belief in fetal pain is very strongly held by pro-life activists. The issue has also surfaced in legislative activity.

United Kingdom

In 2006, an opinion piece by Stuart Derbyshire 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.

In 1996, physiologist Peter McCullagh spoke on behalf of a pro-life group to the British Parliament. He said, "At what stage of human prenatal development are those anatomical structures subserving the appreciation of pain present and functional? The balance of evidence at the present time indicates that these structures are present and functional before the tenth week of intrauterine life."

United States

In the 108th Congress, Senator Sam Brownback introduced a bill called the "Unborn Child Pain Awareness Act" for the stated purpose of "ensur[ing] that women seeking an abortion are fully informed regarding the pain experienced by their unborn child.", which was read twice and referred to committee. Subsequently 25 states have examined similar legislation related to fetal pain and/or fetal anesthesia. Eight states, Arkansas, Georgia, Louisiana, Minnesota, Oklahoma, Alaska, South Dakota, and Texas have passed laws which introduced information on fetal pain in their state-issued abortion-counseling literature, which one opponent of these laws, the Guttmacher Institute founded by Planned Parenthood, has called "generally irrelevant" and not in line "with the current medical literature". Dr. Arthur Caplan, director of the Center for Bioethics at the University of Pennsylvania, said laws such as these "reduce... the process of informed consent to the reading of a fixed script created and mandated by politicians not doctors."

External links

• "Oversight Hearing on Pain of the Unborn" from U.S. Congress, House Judiciary Committee, Subcommittee on the Constitution, Civil Rights, and Civil Liberties (2005). This includes testimony both for and against proposed legislation dealing with fetal pain.
• "Can a embryo or fetus feel pain? Various opinions and studies" from Ontario Consultants on Religious Tolerance. This site states: "We feel that all women considering an abortion should be fully informed and as free as possible from outside pressure."
• Pro-life site presenting case for fetal pain from second month of pregnancy: HTML version.
• Statement of National Abortion Federation Opposing H.R. 3442, the "Unborn Child Pain Awareness Act" (2008): PDF version and HTML version.
• National Right to Life Committee's webpage of testimonies regarding fetal pain: HTML version
• Fetal Pain Research