The hormonal changes that occur in a woman’s body during the nine months of pregnancy are behind the unconditional love that they later feel for their children. In fact, research has determined that the gestation period modifies the nucleus accumbens, a brain structure linked to the experimentation of pleasure, motivation and reinforcement, and causes the mother to “fall in love with her baby” . It is a basic system for maternal behavior in mammals, since it allows the female to feel attracted by the stimuli from the young as soon as she is born.
This study, carried out by the Gregorio Marañón Hospital in Madrid and Cibersam, with the participation of the Autonomous University of Barcelona and the Valencian Fertility Institute (IVI), among other institutions, concludes that, after pregnancy, the baby is It becomes the most striking, relevant and pleasant stimulus for the mother , so that she initiates a series of behaviors aimed at promoting and guaranteeing the survival of the child, as occurs in the animal kingdom.
The coordinator of this study, researcher Susana Carmona, explains that during pregnancy the organs of the pregnant woman change to be able to adapt to the new state, but that, until now, what happens in the brain was unknown . “What we have been able to verify is that the more the brain changes during pregnancy, the more the mother-child bond increases,” he says.
The study analyzed data obtained from new mothers, before and after pregnancy, through brain MRIs. First, it was examined whether there were volumetric changes in the nucleus accumbens and also whether these changes were associated with the activation of this region when the women were shown images of their babies.
The researchers found a decrease in the volume of the nucleus accumbens in women after their first pregnancy. And the more it was reduced, the more this area in the mother’s brain was activated when she saw stimuli related to her son. “In summary, during pregnancy, regions of our brain are modified that facilitate mothers falling in love with their babies,” adds Carmona. These data indicate that maternal behavior in humans is conditioned by primitive and instinctive systems that we share with other more basal mammals, such as rodents.
Determining how women’s brains change during the gestation period can help us “better understand what happens at the brain level in postpartum diseases, such as depression, which put not only the mother’s health at risk, but also the mother’s health. of the newborn ”, points out Carmona.
Research has also shown that, according to MRI tests, these changes in the brain last for at least two years , something that could be related to the fact that, from that moment, the child begins to be more autonomous. However, the scientist anticipates that an attempt will be made to follow up the mothers who participated in the study for six years.
And what about adoptive mothers and fathers?
The sample for this study included 25 first-time mothers and, as a control group, 20 nulliparous women – women who have never given birth. On the activation of the nucleus accumbens in parents and nulliparas, Carmona points out “that there are no studies”. However, animal research seems to indicate that this region is activated “by interaction with the young , even if it requires more time.”
By Sandra Pulido.
