What are the changes in the brain 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 the brains of women during this vital stage.

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

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Changes in a woman's brain during childbearing

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

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

"Hormonal boom"

The changes mentioned appear as a consequence of the great hormonal movement that arose during pregnancy, and have as a direct consequence that mothers "fall in love" madly with their children.

This hormonal movement, which consists of a great 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 throughout a woman's fertile life.

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

Thus, science points out 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 of the mother. This activity, in turn, is related to the mother's primitive and instinctive behaviors towards her baby, aimed at take care of it, protect it and promote its survival.

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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 the changes in the brain during motherhood, an investigation carried out in the Experimental Medicine Service of the Gregorio Marañón Hospital in Madrid and the Ciber de Salud Mental (CiberSAM), by the team led by researcher Susana Carmona and with the collaboration of the Autonomous University of Barcelona (UAB), aims to what the nucleus accumbens undergoes significant changes in its volume during pregnancy. Specifically, its volume decreases.

Research suggests that these changes are directly related to instinctual maternal behavior. This research can be consulted in the journal "Psychoneuroendocrinology" (February 2020).

Objective: the survival of the baby

As we can see, the changes in the brain during motherhood are mainly due to the aforementioned “hormonal boom”, that affects the mesolimbic-dopaminergic system of the brain, mainly, as well as other secondary areas of the same. These changes make the mother's behavior organize herself to attend almost exclusively to her baby. (their development and survival, fundamentally).

Baby "addiction" (infatuation)

The changes in the brain during motherhood make us think of a true "addiction" towards the baby, on the part of the mother, since many of the brain areas that do so when addicted are activated (for example sex, alcohol, smoking ...).

In addition, 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 they so crave.

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

Decreased 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 Neuroscience, reveal that the decrease and changes of the nucleus accumbens allow the baby to be a more striking, pleasant and relevant stimulus for the mother.

In turn, this fact causes the mother's behavior to change and she is directed to protect, care for and love her baby. Such behaviors, logically, would not appear "by themselves" in a woman who has not been a mother.

Necessary addiction?

We have seen how changes in the brain during motherhood are fundamentally involved in an addiction or "infatuation" with baby, which causes a series of instinctive behaviors to be unleashed in the mother, aimed at promoting her integrity and her life (from baby).

In line with all this, we find a very interesting idea from the psychologist Urie bronfenbrenner, and that states that for a baby to develop properly, there must be at least one adult madly in love with him.

Natural pregnancy, in vitro and adoption

A question that may arise in relation to the changes in the brain during motherhood is the following: Do these occur in all "types" of mothers? That is, 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 the parents who adopt, this infatuation or "addiction" of which we spoke would occur, although the hormonal factors would not play the same role, logically. Neither would brain changes, which would not occur. In adoption cases, then, more social and interactive factors would intervene with the baby..

Bibliographic references:

• Carlson, N.R. (2005). Physiology of behavior. Madrid: Pearson Education.
• 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 and Watson, N.V. (2005). Psychobiology: An Introduction to Behavioral, Cognitive, and Clinical Neuroscience. Barcelona: Ariel.