From when does a human fetus feel pain?

From when does a human fetus feel pain?

One of the most frequent and controversial questions that have been generated in the area of sexual and reproductive health, on a par with discussions of abortion legislation and management, is the following: does a human fetus feel pain? In part these discussions have followed the idea that the beginnings of the development of the central nervous system are a sufficient condition to experience pain.

Considering that there is no consensus on how to approach this issue, in this article we present some of the research and theories that have been carried out to discuss the subject.

Can a human fetus feel pain?

In 2006 Stuart Derbyshire, a member of the department of psychology at the National University of Singapore and an expert in cognitive science, discusses this topic taking as its axis a government policy of the United States. The latter determined that it was the doctor’s obligation to warn women who intended to have an abortion about the existence of some indications that abortion may cause pain to the fetus.

From this, the doctor was also obliged to offer the woman the option of reducing such pain by applying drugs before the abortion. The consequence of failing to warn about all of the above could cost doctors thousands of dollars.

On the other side of the world, in England, a series of images were offered at the beginning of the last decade that sought to argue in favour of the idea that the foetus has a series of cognitive and emotional experiences. These images finally influenced British policies on pre-abortion pharmacological interventions to mitigate fetal pain.

Stuart Derbyshire discusses the available evidence on all of the above by analyzing the neurobiological development of the fetal period along with the experiential dimension of pain.

When does fetal development start?

Fetal development is that which occurs from week number 12 . In other words, an embryo is considered to have evolved after the first 3 months of pregnancy.

Over the course of the next 5 or 6 months until delivery occurs, the fetus is expected to develop cells, organs, tissues, and even systems that will be a necessary condition to ensure its birth. Having said this, we will now go on to define what pain is from a psychological perspective, as well as those elements that are considered necessary in order to experience it.

What is pain?

The International Association for the Study of Pain (IASP) says that pain is an unpleasant sensation and emotional experience associated with potential or actual tissue damage , or is an experience described in terms of such damage.

From this we can say that pain is a conscious experience, and not only the response to harmful stimuli (Derbyshire, 2006). With which it is also a subjective experience that can be qualitatively modified between one person and another. Furthermore, for an organism to experience pain, a series of physiologically mature structures are needed . A complex network of cortical regions has to be activated; this can occur even in the absence of real harmful stimulation.

If harmful stimulation is present, it is an external event that generates electrical activity between the brain and the nerves in the skin, which eventually leads to a painful experience. In other words, for an organism to feel pain, there must first be a possibility that the nervous system will be activated .

Likewise, for the experience of pain to occur, other cognitive processes related to the state of consciousness and memory must be developed, which in turn allow us to signify and discriminate an event as “painful” (a question in which the way in which we learn to name this event through others is fundamental).

In other words, although pain is an individual experience (of physiological processes and cognitive processes with which we generate a mental representation of pain), it can also be seen as an experience that is experienced in interaction with others.

Experience of fetal pain and development

It is approximately in the 7th week of gestation when the nerve endings begin to develop, as well as some parts of the spinal cord (which is a fundamental connector of the brain and will lead to the thalamus, an important organ for sensory experiences).

This lays the foundation for creating a hypothalamic structure that is a necessary condition for the experience of pain. But the latter does not mean that the hypothalamic activity is consolidated: the density of the neuronal cells that cover the brain is in the process of consolidation. Before this consolidation is complete, the neuronal cells are not able to process harmful information from the periphery.

In other words, the nervous system is not fully developed and mature, so we can hardly sustain or conclude that pain experience occurs during fetal development.

The first tests of sufficient hypothalamic activity start to occur between the 12th and 16th week of pregnancy . This is when the neural connections within the cerebral cortex begin to mature. Afferent fibers develop from 23 to 25 weeks. However, there is also insufficient functional neural activity to speak of pain experience in the fetus, because the spinal cord fibers in the cerebral cortex plate have not been connected.

Week 26 and other key stages

The thalamic projections on the cerebral cortex plate are the minimum anatomical condition necessary to experience pain, and are completed by the 23rd week of gestation.

Fetal development is that which occurs from week number 12 .
In other words, an embryo is considered to have evolved after the first 3 months of pregnancy.

Over the course of the next 5 or 6 months until delivery occurs, the fetus is expected to develop cells, organs, tissues, and even systems that will be a necessary condition to ensure its birth. Having said this, we will now go on to define what pain is from a psychological perspective, as well as those elements that are considered necessary in order to experience it.

What is pain?

Because this cannot be done with a fetus, scientific research has focused on theorizing about the possibility that there is experience of pain through analyzing the embryonic development of the nervous system . From there they suggest that the experience of pain exists because it is similar to that already verbalized by a child or an adult.

That is, research has had to resort to the interpretation of secondary evidence, and for the same reason has only been able to speak of clues, not conclusive results about the experience of pain in fetal development.

In summary

To feel pain not only we need the ability to discriminate between different sensory stimuli . Nor is it a matter of reacting to potentially harmful stimuli (a quality known as "nociception"). The experience of pain also implies responding in a conscious way, that is, we also need the capacity to discriminate between different experiences; a question that is generated by the interactions with our caregivers after birth, among other processes such as the development of the mind.

We therefore need a mature nervous system that allows us to process and represent such stimuli as harmful and subsequently as painful.

There are numerous important neurobiological processes that start at week 7, week 18 and week 26 of gestation . These have been considered by many to be the stages where a human fetus might feel pain. What Derbyshire (2006) quickly warns us is that the subjective experience that accompanies pain cannot be directly deduced from anatomical development, as these developments are not the ones that give rise to the conscious contents of pain itself.

Bibliographic references:

  • Derbyshire, S. (2006). Can fetuses feel pain? BMJ, 332: 909-912.

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