Neuroscience confirms: having a child reduces the brain of fathers and mothers

In November 2008, Susana Carmona, then a post doctoral student of neurosciences took two colleagues to a party, when one of them commented that she was thinking of having a child. The three engaged in discussing the changes that could occur in the brain And in the end, instead of going to the party, they went to the laboratory of the Autonomous University of Barcelona to look for literature on the matter.

All they found was a series of studies on changes during pregnancy in the brain of rodents. Of humans nothing, so the next day the three went to talk to their boss, Oscar Vilarroya to raise a study that would measure the neuroanatomy of women with a magnetic resonator, before and after becoming pregnant.

The project, which was one of the many that followed, took years and included dozens of participants. When in 2016 they announced the results they were revealing: two or three months after giving birth to many regions of the maternal cerebral cortex were reduced on average 2%, with respect to the prior volume to conception (pregnancy leads to long-the changes in human brain structure, e.hoekzema et al, 2016).

In 2022, Elsine Hoekzemaone of the three originals, then working at the Medical Center of the University of Amsterdam confirmed with another job that The brain regions that were also reduced by differently worked for at least a year (Mapping the Effects of Pregnancy on Resting State Brain Activity, White Matter Microstructure, Neural Metabol Concentrations and Gray Matter Architecture ”, E.Hoekzema et al, 2022).

The funny thing is that hundreds of surveys have been conducted and between 50% and 80% of the 140 million women who go through a pregnancy a year have reported memory deficits, a “brain mist” and other cognitive problems (A review of the impact of pregnancy on memory function, JD Henry and Prendell 2007). The signs were known a long time ago, and despite the fact that numerous studies are now being carried out in this regard, this field of science remains in their childhood.

Pregnancy

The physiological changes generated by pregnancy in the body of mothers are brutal and they are heading to transform the body into a vehicle to allow the development of the offspring.

Studying this in the case of human is much more complicated than in another animals, because many of the changes in behavior are more subtle and the physiological effects coincide with psychosocial and environmental changes.

One of the typical examples in this regard are hormonal changes (The Descent of Man´s Testoterone, Pbgray, 2011) and brain alterations that suffer from the parents -Necaminated to be “more protective” of your partner- and that although they are less significant they run in parallel with those of the mothers (The Neural Mechanisms and Concequences of Paternal Caregiving, by R.Feldman et al 2019).

The changes

There are many regions of the brain that are reduced (none grows), the Ventral stratumwhich has to do with the “reward” processes; he hypothalamuskey to the control of instinctive behaviors; he hippocampusEssential Parties The Memory and the Modal network circuitwhich is involved in social processes such as empathy, the theory of mind and dreaming awake (think about and understanding others and oneself). But above all, the crustthat integrates information from other regions of the brain and that makes us essentially different from other animals, it is reduced on average almost 5% during pregnancy (pregnancy enntails to U-Shaped Trabectory in Human Brain Structure Llinked to Hormone and Matternal Attachment, by C. Servin Barthet et al, 2024.pdf).

These changes are probably induced by hormones and except what happens with the modal circuit, They tend to be reversed quickly and totally after birth (Evidence of Subjective But Not Objective Cognitive Deficit in New Mothers at One Year Postpartum by Erorchard et al, 2022), which is logical: what happens with the network correlates with the strength of the mother/row link, the behaviors of “anidings”, the response to images of babies and the problems in the process of linking with the process. In fact, Mothers who show the greatest reduction in the volume of “gray matter” tend to be the ones that have the strongest links with the newborn.

It is important to understand that this reduction is not a “deficit”, but a refinement of neural functions, which is usually called “synaptic pruning” (There seems to be no decrease in the number of neurons). It has been detected that during adolescence, when humans move on to a more independent stage, there is also a reduction, which, as in the case of pregnancies, is accompanied by a “flattening” of the folded structure of the cortex, in this case to cement that someone depends on one.

It is true that 17% of first-time mothers (especially in low and middle income countries) suffer from postpartum depression (and that although it is not significant, more cases of psychosis and obsessive-compulsive disorders) are recorded; However, the evidence suggests that the brain of women who have had children look on average 7 months older than those who have not had them (population-base neuroimaging reveals traces of Childbirth in the maternal brain by am g of lange et.al. 2019) and that regardless of sex, the brain of the middle-aged parents seems to be younger from a functional point of view from a functional point of view Better connected the more children have been (Protective Role of Parenthood on Age-Related Brain Functions in Mid To Late Life by Erorchard et.al, 2025)

The father

That happens to women what happens to them in the brain during pregnancy is reasonable and logical. We have long known that the surprising thing is that it has been seen that the same phenomenon of brain reduction is recorded in parents.

In a job following 20 Spanish parents, 20 Americans and 17 Spaniards who had no children as control, a team led by Magdalena Martínez Garcíaof the Gregorio Marañón Research Institute of Madrid (First Time Fathers Longitudinal Show Gray Matter Cortical Volume Redrance Evidence from TWO International Samples by M.Martinez Garica Et.al, 2022), found that the cerebral cortex of those who had a child was reduced, especially in the rear area, similar to what happened with the mothers but less pronounced, more pronounced, more pronounced, more varying and possibly for other mechanisms

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Changes in the brain of mothers, fathers and men without children (The Parental Transition Entails Neuroanatomic Adaptations that are associated with fathers brain response to infant cen

As in the case of women, Those men who registered the greatest decrease in brain volume were those who showed the greatest link with babies, were their own or others. They were also those who reported a lower level of parental stress and who spent more time with their children.

Of course, nothing is free, a higher level in the decrease in gray matter would also be associated with major problems in sleep, anxiety and psychological stress and postpartum depression, which would tend to disappear as babies grow (cortex volume reduces in men M.Martinez Garcia 2024)

For now, we do not know what is a mechanism of cerebral reduction in men, unless it leads to the same evolutionary objective, making sapiens one of the few mammals (5% and 10% of primates; The Evolution of Male Parental Investment in Mammals, Dgkleiman & Jrmalcom, 1981) in which the parents are responsible for the parenting and care of the pro. Mothers, what the most successful mammal has done to us on earth.