Pregnancy and the brain. A child changes your life, starting with your brain
A child does not just change your life - it also changes your brain, and not just during pregnancy and lactation but over the long term. This is something that we have been able to demonstrate visually with no room for doubt, by means of neuroimaging. This is the surprising conclusion reached 2016 by the study led by Òscar Vilarroya and the researchers of the Cognitive Neuroscience Research Unit at the Department of Psychiatry and Legal Medicine of the UAB and the IMIM Neuroimaging and Mental Disorders Research Unit, in collaboration with the Valencia Infertility Institute (IVI).
What is most interesting is that, until now, the changes in the brain caused by the fact of having a baby have been studied little and more often in animals than in humans, so this was a virtually unknown field. If small mammals undergo microscopic and macroscopic changes at the structural and functional level, why should humans be any different? What changes would we find during pregnancy and lactation? Would they be the same for mothers and fathers? Would they be maintained over time? And how could we visualize and show them?
The major changes in the brain of the mother during pregnancy involve specialization to meet the challenges of motherhood. There is no loss at the cognitive level nor any intellectual deterioration. On the contrary, it appears to be a highly practical adaptive restructuring of the brain - forced learning aimed at increasing sensitivity when detecting threats to or the emotional state of the newborn.
The study that answers all these questions compared the magnetic resonance imaging of 25 pregnant women before delivery and six months afterwards, 19 of their male partners, and 20 women who were not and who had never been pregnant, as well as 17 of their male partners. In total, the study involved five years and four months of research with thousands of cortical images to analyze and compare.
Nature changes you so that you focus on the baby
Women in their first pregnancy are subject to extreme hormonal changes and incredible biological adaptations that definitively affect their brain structure. During pregnancy, the brain, like the rest of the body, appears to also undergo nesting behavior, which prepares it to meet the new situation. This was shown by the resonance images taken of the women taking part in the study; the images were radically different in those who were not pregnant and it was possible with the images alone to deduce which group each woman belonged to.
What happens to the brains of pregnant women during those months, with no differences between those who conceived naturally and those who underwent assisted fertility treatments, is a reduction in the grey matter in regions of the brain involved in social relations. There is a symmetric reduction in the volume of gray matter that appears to be maintained over time, as it can still be detected two years after delivery. Furthermore, the images showed structural changes that can predict the level of bonding between the woman and her child.
What is the effect of this modification of the brain architecture? The researchers state that the major changes in the brain of the mother during pregnancy involve specialization to meet the challenges of motherhood. There is no loss at the cognitive level nor any intellectual deterioration in women, as was shown. On the contrary, it appears to be a highly practical adaptive restructuring of the brain - forced learning aimed at increasing sensitivity when detecting threats to or the emotional state of the newborn. Nature ensures that the new mother stops occupying the brain with thinking about herself and is able to focus on the survival and protection needs of others; in this case, the new life that she will have to take care of. The researchers compare this process to the synaptic pruning that takes place during adolescence, where weak synapses are deleted to encourage more mature mental processing, aimed at inferring the needs of the baby.
What happens to men?
The reduction of gray matter during pregnancy and lactation is exclusive to women, as none of the male partners showed similar changes.
It therefore appears that these modifications can be attributed to biological processes in pregnancy and not to other changes related to the birth of the child (emotions, acquired responsibility), which fathers can also experience. This does not mean that fathers cannot care for their children with all their affection, naturally... it simply means that their brain does not cooperate as much as the mother’s brain naturally does.
Pregnancy changes the brain: transitioning into motherhood involves long-lasting alterations in human brain structure. Nature Neuroscience.