Pregnancy comes with massive changes in a mother’s body, leaving behind signs of being pregnant like stretch marks and weight gain. The body takes a massive toll when harboring and caring for another life, and doesn’t ever return to its pre-pregnancy state. Even though weight loss and fitness can keep the body looking like it was before, internal organs like the uterus are affected for the rest of the woman’s life. A recent study done by researchers at the Universitat Autonoma de Barcelona has shown that the brain also changes drastically during pregnancy, and remains that way for at least 2 years.
The study consisted of 25 first-time mothers and 19 male partners, as well as a control group of 20 women that had never been pregnant and 17 male partners. The study spanned over 5 years where the participants were tracked and recorded. All participants went through an MRI scan before the control group women conceived, and again after the women gave birth. The results showed a distinct difference in the new mothers’ brains as compared to the new fathers as well as the control group. There was a significant loss of grey matter volume in the medial and posterior cortex, as well as in the prefrontal and temporal cortex.
These parts of the brain are responsible for social cognition, emotional intelligence and empathy among other things. Though a shrinkage in brain matter sounds bad, it isn’t necessarily so. The study’s co-author, Elseline Hoekzema says that “Loss of function does not necessarily translate to a loss of function. Sometimes less is more.” This could be seen as an alert for the brain to fine-tune these areas to make the transition into motherhood easier. The other time when the body and brain go through changes the release of large quantities of hormones like estrogen and progesterone is during puberty.
There is a “pruning” of neuronal connections and grey matter during adolescence too because the brain is maturing and strengthening connections to transition into adulthood. It could be possible that a new mother’s brain reaches another level of maturation needed to take care of her child for the rest of her life. The changes in the brain lasted for at least 2 years, after which the study ended. Further studies are needed to see the extent of how long these changes can last. This study also took into account naturally conceiving mothers as well as mothers that needed fertility treatments to get pregnant: the brain changes were near identical in both.
The researchers also used a scale to rate the attachment between the mothers and the newborns. Using a computer, they created algorithms that could identify and separate a new mother from someone who had never been pregnant by scaling their grey matter volume. The rates of attachments were then compared to the loss of grey matter; and the results showed that the mother that had the greatest volume loss also had the highest attachment with their newborns. Now, MRI scans are enough to differentiate between a mother and someone who hasn’t yet had a child. Though scientists don’t have a conclusive reason for these brain changes, they believe that this is an evolutionary mechanism to help women cope with motherhood. The “specializing” in areas of empathy and social cognition can help mothers to identify when their child needs something. The ability to recognize the cues to feed a child, or to change a child among other functions that is based on facial expressions is important for all first-time mothers.
Though this was a small study, its results open up a pathway to more studies that could be significant in the future. This is a first study of its kind, pointing to a new direction in the role of the brain in pregnancy and motherhood. The brain changes are certainly something to study further, leading to a new kind of thought and function for new mothers.