What do we know about the changes in a woman’s brain during childbearing?
Have you ever wondered if changes occur in the brain during motherhood? Science has provided an answer to this question, and recent studies reveal that changes do indeed occur in women’s brains during this life stage.
But what kinds 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 IVF or in mothers who adopt? In this article we will solve all these questions.
Changes in a woman’s brain during childbearing
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 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 motherhood.
The aforementioned changes 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 dopamine acts as both a neurotransmitter and a hormone. 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 from the mother. This activity, in turn, is related to the mother’s primitive and instinctive behaviors towards her baby, aimed at caring for, protecting and promoting 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 the changes in the brain during maternity, 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), it points out that the nucleus accumbens undergoes important 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).
Goal: 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 it. These changes make the mother’s behavior organized to attend almost exclusively to her baby (its 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 in the face of an addiction are activated (for example to sex, alcohol , to smoke…).
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 techniques of magnetic resonance imaging (MRI). The decrease in the size of this structure is related to the mentioned 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.
We have seen how an addiction or “infatuation” with the baby intervenes in the changes in the brain during motherhood, which causes a series of instinctive behaviors to be unleashed in the mother, aimed at promoting her integrity and her life (of the baby).
In line with all this, we find a very interesting idea from the psychologist Urie Bronfenbrenner, who 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 changes in the brain during motherhood is the following: do these occur in all “types” of mothers? In other words, 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 parents who adopt, this infatuation or “addiction” of which we spoke would occur, although hormonal factors would not play the same role, logically. Neither would brain changes, which would not occur. In adoption cases, then, factors more of a social and interactive nature with the baby would intervene.
- Carlson, NR (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, MR, Breedlove, SM and Watson, NV (2005). Psychobiology: An Introduction to Behavioral, Cognitive, and Clinical Neuroscience. Barcelona: Ariel.