A growing body of science reveals an undisputable fact: unborn babies can feel pain by 20 weeks post-fertilization,[1] and most likely even earlier. As the medical community continues to increase its understanding of fetal pain, there have also been increasing legislative efforts to protect the unborn child from cruel suffering.

Pain (nociception) is an aversive response to a physically harmful or destructive stimulus. The National Institutes of Health define pain as a basic bodily sensation that is induced by a noxious stimulus, is received by naked nerve endings, is characterized by physical discomfort (as pricking, throbbing, or aching), and typically leads to evasive action.[2]

Unborn babies 20 weeks post-fertilization not only have the anatomy to process pain but also the neurobiology to transmit painful sensations to the brain and perceive pain. Dr. Jean A. Wright, testifying at a Congressional subcommittee hearing summarized it best:

After 20 weeks of gestation [18 weeks post-fertilization], an unborn child has all the prerequisite anatomy, physiology, hormones, neurotransmitters, and electrical current to close the loop and create the conditions needed to perceive pain&The development of the perception of pain begins at the sixth week of life. By 20 weeks [18 weeks post-fertilization], and perhaps even earlier, all the essential components of anatomy, physiology, and neurobiology exist to transmit painful sensations from the skin to the spinal cord and to the brain.[3]

There is no question, biologically speaking, about whether an unborn child can feel pain by 20 weeks post-fertilization. By 18 weeks post-fertilization, nerves link pain receptors to the brains thalamus (the pain processing center). By 18 weeks post-fertilization, the cerebral cortex (the region of the brain associated with higher mental functions) has acquired a full complement of neurons, meaning all of the neurons are present, though not all the connections in the cortex are fully developed until later. EEG activity, a recording of electrical activity in the brain, appears for the first time at 18 weeks post-fertilization, showing the integrity of the circuitries of the cortex and the thalamus. [4]

Source: Arina Grossu, http://frc.org