From when does a human fetus feel pain?

A controversial issue: what is the moment in development when the capacity to feel Pain appears?

One of the most frequent and controversial questions that have arisen in the area of sexual and reproductive health, along with discussions on 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 for the experience of pain.

Considering that there is no consensus on the approach to this question, in this article we present some of the research and theories that have been conducted to debate the issue.

Can a human fetus feel pain?

In 2006 Stuart Derbyshire, a member of the psychology department of the National University of Singapore and an expert in cognitive science, discussed this issue using a U.S. government policy as the focus. The latter determined that it was the physician's obligation to warn women who intended to have an abortion about the existence of some about the existence of some indications that abortion may cause pain to the fetus.

From this, the physician also had the obligation to offer the woman the option of reducing such pain through the application of drugs prior to 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 for the idea that the fetus has a range of cognitive and emotional experiences. These images eventually had an impact on British policies on pre-abortion pharmacological interventions to mitigate fetal pain. 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 begin?

Fetal development is that which occurs from the 12th week onwards.. That is to say that the embryo that has evolved after the first 3 months of gestation is considered a "fetus".

In the course of the following 5 or 6 months until delivery, 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 define what pain is from a psychological perspective, as well as those elements that are considered necessary to be able to experience it.

What is pain?

The International Association for the Study of Pain (IASP) says that pain is an unpleasant sensation and an emotional experience associated with potential or actual tissue damage, or it is an unpleasant experience of pain.or it 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 noxious stimuli (Derbyshire, 2006). Thus, it is also a subjective experience that can be qualitatively modified from one person to another. Furthermore, in order for an organism to experience pain, a series of physiological structures are needed a series of physiologically mature structures are required for an organism to experience pain.. A complex network of cortical regions must be activated; this can occur even in the absence of actual noxious stimulation.

If noxious stimulation does occur, the latter is an external event that generates electrical activity between the brain and the nerves of the skin, which ultimately generates a painful experience. That is to say, for an organism to feel pain, there must first be the possibility that the nervous system is activated..

Likewise, in order 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 the meaning and discrimination of an event as "painful" (an issue in which the way in which we learn to name such an event through others is fundamental).

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

Pain experience and fetal development

It is at about week 7 of gestation that the nerve endings begin to develop, as well as parts of the spinal cord (which is a fundamental connector of the brain and will give rise 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 neuronal cells lining the brain is in the process of consolidation. Before such consolidation is complete, neuronal cells are unable to process noxious information from the periphery. from the periphery.

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

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

The 26th week and other key stages

Thalamic projections in the cerebral cortex plate are the minimum anatomical condition necessary to experience pain, and are completed by the 23rd week of gestation. At the same time, the peripheral nerve terminals that will generate reflexes in the cerebral cortex develop.

For this reason, several investigations have suggested that the minimum gestational week to suspect the experience of pain in the fetus is week 26 (around 7 months of gestation), which is when the electrical activity is similar to that of children and adults. similar to that presented by children and adults when they respond to noxious situations, or when they explain a pain experience in the fetus.or when they explain an experience as painful.

On the other hand, the secretion of different hormones is also necessary; a process that begins to be observable in fetuses from the first 18 weeks of gestation.

The problem, as Derbyshire (2006) tells us, is that what happens inside the placenta is significantly different from what happens outside the placenta, both in neurochemical terms and in the way it responds to noxious stimuli, and therefore on sensitive experiences.The most classic studies on pain experiences have consisted of relating the electrical activity of the brain to the experience of pain, both in neurochemical terms and in the way of responding to noxious stimuli, and therefore on the sensitive experiences.

In this same sense, the most classic studies on pain experiences have consisted of relating the electrical activity of the brain to the experience of pain that is reported verbally by the same person.

Because this cannot be done with a fetus, scientific research has focused on theorizing about the possibility that the brain's electrical activity may be related to the experience of pain. theorizing about the possibility of pain experience by 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 indications, not conclusive results about the experience of pain in fetal development.

In summary

In order to feel pain, we not only need 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 involves responding consciously, i.e., we also need the ability to discriminate between different experiences; a matter that is generated by interactions with our caregivers after birth, among other processes such as the development of the mind.

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

There are numerous important neurobiological processes starting 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.

Bibliographical references:

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