What are the changes in the brain during motherhood?

What do we know about the changes a woman's brain undergoes during motherhood?

Have you ever wondered if changes occur in the brain during motherhood? Science has provided an answer to this question, and the latest studies reveal that changes do indeed occur in women's brains during this vital stage.

But what kind of changes occur, mainly? What brain structures are involved? What effect do these changes have on the mother's behavior? Finally, does the same thing happen in mothers who conceive naturally as in mothers who undergo in vitro fertilization or in mothers who adopt? In this article we will resolve all these questions.

The changes in a woman's brain during maternity

The changes in the brain during childbearing are mainly located in a brain structure called the nucleus accumbens. The nucleus accumbens is a very primitive part of the brain, related to pleasure, gratification and reward..

It activates our motivation and allows our will to guide our actions. It is also related to learning, memory, fear, aggression, addictions, laughter... and to very basic and primitive needs, such as sex or food intake. Later we will talk in more detail about this structure and its relationship with the changes in the brain during motherhood.

"Hormonal boom".

The above-mentioned changes appear as a consequence of the great hormonal movement that arises during pregnancy.The direct consequence of these changes is that mothers fall madly in love with their children.

This hormonal movement, which consists of a large synthesis of different hormones, is very intense and abrupt; in fact, it is generally considered to be even greater than the hormonal change that occurs during a woman's entire fertile life.

These changes occur mainly in the mesolimbic-dopaminergic system of the brain, where dopamine acts as a hormone that is responsible for the hormones that are produced in the brain.where dopamine acts as both a neurotransmitter and a hormone. Dopamine is involved in pleasurable behaviors, in the regulation of motivation, in desire and in the repetition of certain behaviors (especially those that are reinforcing for us).

Thus, science suggests that during pregnancy there is a modification of the activity of the nucleus accumbens, as we have seen, a structure closely related to obtaining pleasure and reinforcement, in this case from the mother. This activity, in turn, is related to the mother's primitive and instinctive behaviors towards her baby, aimed at caring for it, protecting it and promoting its survival. care for it, protect it and promote its survival..

The importance of the nucleus accumbens: what does science say?

We have seen how the nucleus accumbens is a brain structure related to different human sensations, needs and emotions; learning, pleasure, motivation, fear....

In relation to it and to the changes in the brain during maternity, a research carried out at the Experimental Medicine Service of the Gregorio Marañón Hospital in Madrid and the Ciber de Salud Mental (CiberSAM), by the team led by the researcher Susana Carmona and with the collaboration of the Universitat Autònoma de Barcelona (UAB), points out that the nucleus accumbens undergoes significant changes in its volume during pregnancy. Specifically, their volume decreases.

Research suggests that these changes are directly related to instinctive maternal behavior. This research is available in the journal "Psychoneuroendocrinology" (February 2020).

Objective: survival of the baby

As we can see, the changes in the brain during motherhood are mainly due to the aforementioned "hormonal boom", which affects the mesolimbic-dopaminergic system of the brain, mainly, as well as other secondary areas of the brain. These changes cause the mother's behavior to be organized to attend almost exclusively to her baby (mainly its development and survival). (its development and survival, fundamentally).

"Addiction" to the baby (infatuation)

The changes in the brain during maternity make us think of a real "addiction" towards the baby, on the part of the mother, since many of the same brain areas are activated that are activated in the case of an addiction. (e.g. sex, alcohol, smoking...).

Moreover, in the face of an addiction, all the structures and the different brain systems are coordinated so that the individual obtains the reinforcement and/or motivation that he/she craves so much.

But what does this "addiction" translate into? what does this "addiction" translate into at the brain level? In a study developed by the Valencian Infertility Institute (IVI) in Barcelona, carried out with 25 women (new mothers) and 20 control women (who were not mothers), a decrease in the volume of the nucleus accumbens was observed through magnetic resonance imaging (MRI) techniques. The decrease in the size of this structure is related to the aforementioned addiction.

Decrease of the nucleus accumbens

The results of this study, which are in line with the results obtained by the same team three years earlier, in 2017, through a study published in Nature Neurosciencereveal that the decrease and changes in the nucleus accumbens allow the infant to be a more attractive, pleasurable and relevant stimulus for the mother. for the mother.

In turn, this fact causes the mother's behavior to be modified and directed towards protecting, caring for and loving her baby. Such behaviors, logically, would not appear "on their own" in a woman who has not been a mother.

Necessary addiction?

We have seen how the changes in the brain during motherhood involve, fundamentally, an addiction or "falling in love" with the baby, which unleashes a series of instinctive behaviors in the mother, aimed at promoting her integrity and her (the baby's) life.

In line with all this, we find a very interesting idea of the psychologist Urie Bronfenbrenner, which states that for a baby to develop properly, there must be at least one adult who is madly in love with it.

Natural pregnancy, in vitro pregnancy and adoption.

A question that may arise in relation to changes in the brain during motherhood is the following: Do they occur in all "types" of mothers? That is to say, in mothers who conceive naturally, in mothers who have undergone in vitro fertilization... well, the answer is yes, in all of them.

On the other hand, in fathers and mothers who adopt, this infatuation or "addiction" we were talking about would occur, although hormonal factors would not play the same role, logically. Neither would brain changes, which would not occur. In cases of adoption, therefore, more social and interactive factors would intervene with the baby..

Bibliographical references:

• Carlson, N.R. (2005). Physiology of behavior. Madrid: Pearson Educación.
• Hoekzema, E., Tamnes, Ch., Berns, P., Barba-Müller, E. et al. (2020). Becoming a mother entails anatomical changes in the ventral striatum of the human brain that facilitate its responsiveness to offspring cues. Psychoneuroendocrinology, 112.
• Rosenweig, M.R., Breedlove, S.M y Watson, N.V. (2005). Psicobiología: una introducción a la neurociencia conductual, cognitiva y clínica. Barcelona: Ariel.