While the physical and physiological effects of pregnancy on a woman’s body are obvious, its impact on the brain is less well understood. We are talking about an amazing organ, made up of plastic neural networks. This means that life experiences, such as a pregnancy, can change these circuits and their structure.
hormonal stir
During pregnancy, changes occur that lead to the production of sex hormones such as estrogens and the progesterone, necessary to maintain the pregnancy and prepare the woman for the birth of the baby. Both have a great effect on the brain, since they control the shape and number of neurons.
This phenomenon has been demonstrated during puberty, when estrogen and progesterone increase and cause behavioral, cognitive, and emotional changes in adolescent girls. Something similar appears to occur during pregnancy, although less has been studied so far.
First, the increase in estrogens can lead to changes in the brain’s ability to learn and make decisions. It is also capable of producing a positive effect on mood and mood. emotional well-being.
Regarding progesterone, studies indicate that it generates an increase in the expression of cytoskeletal proteins (a network of proteins that provide internal support to the cell) of the hippocampal region. This may involve increased plasticity of synapses, the connections between neurons.
However, how these hormones affect memory is not yet fully understood. More research is needed to better understand its role.
Shrinks gray matter, but this is positive
Changes observed in the pregnant woman’s brain include a reduction in the volume of the gray matter, the area of the brain made up primarily of neuronal cell bodies. In addition, the width of the grooves and the size of cavities called ventricles increase, while the thickness and surface area of the cortex decreases. However, after the birth of the baby, these modifications are reversed and the brain grows again.
Although the loss of gray matter seems detrimental at first glance, it supposes the opposite: this loss may represent a fine adjustment of the connections. This is what happens in the adolescent brain when a flood of hormones triggers the general pruning of synapses and generates more efficient brain circuits.
The changes, region by region
If we look at the different areas of the pregnant brain, the most prominent modifications are the following:
1. Enlargement of the tonsil. Its main function is the processing of emotions. During pregnancy it can cause depressive states and anxiety.
2.Increase in the size of the pituitary gland. It is known as the “master gland” because it produces hormones that affect many bodily functions. In pregnancy, your role might be to create a mother-son emotional bond.
3. Decreased volume of the hippocampus, an important area for memory and emotional regulation.
4.Increased activity of the precuneus. This area is responsible for integrating internal brain information with external environmental information. It seems to help the mother become aware of her body, allowing her to focus on the development of the newborn.
5.Increased activity of the cingulate gyrus, the prefrontal cortex, and the orbitofrontal cortex. It also seems to be related to the generation of bonds between the mother and the child.
Minds tuned to take care of the baby
Therefore, the changes that the brain undergoes during pregnancy affect structures involved in social cognition, the ability to discover what another person is thinking and feeling.
These alterations, which favor socio-affective processes, can be understood as a adaptive advantage. Enhanced social cognition promotes mother-child bonding and help mother take care of her baby and to recognize their needs by decoding infant sounds and cries. In addition, it allows the parent to interpret social stimuli that may announce a threat.
However, improvements in social cognition may come at a cost. Many women report experiencing memory problems, a phenomenon called “pregnancy brain«. Spatial memory, for example, might suffer late in gestation because it is not critical to offspring’s survival during that period.
On the other hand, several authors suggest that the brain changes associated with pregnancy could have implications for the long-term mental health and well-being of mothers. In support of this idea, some studies indicate that it may confer protective effects against aging.
Thus, for example, middle-aged parents have a faster response and make fewer errors in visual memory tasks than people without children. In addition, individuals over 70 years of age with offspring have greater cortical thickness and better verbal memory, which suggests that maternity and paternity may be neuroprotective during aging.
More research is needed
In summary, pregnancy has significant effects on maternal brain structure and function, including changes in gray matter, neural connectivity, and brain plasticity. These modifications explain the close psychological bond that the mother creates with the newborn. They could also shed light on why some women are more prone to developing postpartum depression.
However, more research is needed in this regard, as only a few dozen studies exploring the impact of pregnancy on the female brain have been conducted in the last century. In addition, these studies have been carried out on a small number of women.
This article was originally published on The Conversation.