The mystery of life. For nine months, the body of the pregnant woman undergoes many transformations as it “manufactures” the unborn child. Her belly is growing, but that’s only the tip of the iceberg. Thus, throughout pregnancy, the brain of future mothers is also subject to multiple modifications, preparing them for the new role that awaits them.
In their work In the minds of mothers (ed. du Rocher), Dr Hugo Bottemanne, psychiatrist, head of clinic at the Pitié-Salpêtrière hospital and neuroscience researcher at the Institut du Cerveau (ICM) and Dr Lucie Joly, psychiatrist, head of perinatal adult psychiatry in the Saint-Antoine, Pitié-Salpêtrière, Tenon, and Trousseau hospitals in Paris, decipher the mysteries of perinatal neuroscience and reveal some secrets to 20 Minutes. Why are pregnant women sometimes a little in the moon? How is the bond between mother and baby built from the start of pregnancy?
Le « mommy brain »
Having a floating mind, memory lapses, being a little dizzy are all traits that can be observed in many pregnant women. “What is called the ‘mommy brain’, or ‘mamnesia’, designates these cognitive, memory or inattention disorders that one can have during the pregnancy, explains Dr. Lucie Joly. During these nine months, the architecture of the brain changes: this is perinatal neuroplasticity. Studies have observed a decrease in brain size of 5 to 10%. This obviously does not mean that the woman is less intelligent! Her brain acquires particular specificities to prepare her for the arrival of the infant and to better respond to her needs”.
A mommy brain which would affect regarding four out of five women and which might be caused by a drop in the blood supply to the brain, associated with a reduction in its oxygenation and its activity. An energy reallocated to the fetus by the body of its mother, detail the two psychiatrists in their work. “But without causing the slightest cerebral sequelae,” reassures Dr. Joly.
Another effect of this mommy brain: a zenitude almost foolproof often observed. “It’s a progressive mechanism that reaches its peak in the third trimester, where we really observe this rather surprising maternal serenity, like a feeling of being on a cloud, in a bubble, describes Dr Hugo Bottemane. The relationship to negative things is quite distant”.
Interoception and the construction of the maternal bond
If there is one moment that future mothers watch for, it is when they feel their baby for the first time. And which makes like small bubbles which fizz in their belly. First movements in utero collected between the end of the third and the fifth month, before the baby to be born grows bigger and kicks outright. During this time, the mother’s body adapts to this life which is growing inside her and provokes sensations which already participate in the construction of the maternal bond, giving rise to the love she has for her baby, who has no yet not seen the light of day.
“We wanted to bring the notion of interoception – all the perceptions we have of our body, how the viscera are positioned… – in perinatal care. This takes a new look at the role of the perception of fetal movements in the creation of maternal attachment”, explains Dr. Joly, who is currently conducting a study on the subject with his colleague. “We wanted to study the weaving of this maternal love in terms of psychology and communication between the body and the brain”, adds Dr Bottemane. Perinatal interoception which “can be worked with certain tools such as haptonomy, to work on the prenatal bond and promote attachment with the baby”, continues Dr. Joly.
But this perinatal interoception can sometimes play funny tricks on mothers’ brains, and cause phantom baby syndrome. “It’s the fact of feeling the movements of the baby who is no longer in the belly, following childbirth, says Dr. Joly. It is explained by interoception: the body keeps the memory of the passage of the baby, and in this context, the sensory cortex can be disturbed and create the illusion of a fetal movement, but without a baby”. A phenomenon “similar to that of phantom member, but very little described. In our study of 4,000 participants, 40% of the women questioned indicated that they had felt phantom fetal movements, observes Dr. Bottemanne. It remains to be discovered whether on the cerebral level, in women who continue to experience these sensations, these are the same areas of the brain as those which are activated in the perception of movements during pregnancy.
Activation of mothers’ “vigilance mode”
And when the child is born, have you ever noticed how the mother is particularly sensitive to crying baby ? “All the cerebral modifications during pregnancy, in particular at the level of the reward circuit, are to prepare the mother to be more vigilant to these signals”, confirms Dr. Joly. Thus, “following childbirth, studies have shown that activity in this reward circuit increases when mothers see their babies smile or when they hear them cry,” explain the two psychiatrists.
But “the construction of this bond and this maternal sensitivity are progressive: the mother will first be more sensitive to the crying of babies, then focus gradually and specifically on the signals emitted by the child”, note Drs Joly and Bottemane. But this vigilance, “the other parent – or the adoptive parents – can also work on it, reassures Dr Bottemane. It is an apprenticeship”.