During pregnancy, women undergo various changes in their bodies and behaviour. newly Nature Communications The study evaluated pre- and post-conception brain scans to better understand changes in gray matter structure, diffusion measures of neurotransmitter concentration, and temporal coherence of neural networks. In addition, biological factors associated with these changes were evaluated in this study.
Pregnant women go through a tremendous transition related to a series of endocrine glands and various adaptive changes in the body. Almost all body systems change during pregnancy, and some physiological changes remain constant for decades after birth. Limited evidence of changes in the human brain during and after pregnancy has been documented.
Several non-human animal models have indicated a correlation between reproduction and brain plasticity. These studies indicated significant changes in the mammalian brain and behavior.
According to a recent study, pregnant women change the structure of gray matter in the human brain. The current study went further to analyze changes in pregnant women’s neuronal metabolite concentrations, neural network organization, and white matter microstructure using a comprehensive prospective study cohort.
In this study, four longitudinal experimental sessions were included, and participants were followed from pre-pregnancy to the late postpartum period. Analytical tools, such as diffusion-weighted imaging, anatomical magnetic resonance imaging (MRI), resting-state fMRI acquisition, and 1H NMR spectroscopy, have been used to investigate the effect of load on human brains.
Changes in hormonal profiles were evaluated to analyze the mechanism underlying pregnancy-related neuroplasticity. Maternal hormone levels were determined using biological samples collected every four weeks of pregnancy. The participants’ sleep pattern and stress levels were also recorded.
Changes in brain scans over the study period were recorded in a chart. Specific structural and functional brain plasticity that may contribute to maternal adaptation during pregnancy has been observed.
Compared to non-pregnant women, a distinct gray matter structure was found in pregnant women. A decrease in gray matter volume has been observed in pregnant women, affecting the anterior and posterior cortical midline and specific parts of the lateral lateral prefrontal and temporal cortex.
Magnetic resonance spectroscopy, diffusion-weighted imaging, and resting-state fMRI data did not reveal a significant difference in measures of white matter diffusivity or volume between the groups of pregnant and unborn women (control group). This result indicates that the anatomy of a woman’s white matter remains stable throughout pregnancy.
Fluctuations in sex steroid hormones were strongly selective for some components of the brain, that is, steroid hormones affect brain gray matter much more than white matter structure. Magnetic resonance spectroscopy data showed no change in neurotransmitter concentrations during pregnancy.
The default mode network (DMN) corresponds to a group of coherently active, highly active brains that remain highly active even without a specific task. Hence, the DMN reflects the underlying activity of the individual brain. It is also strongly involved in higher-level social processes, such as social evaluation, social cognition, and empathy.
MRI data on women’s resting state decoding neural network organization of pregnant women. This analysis revealed a selective increase in DMN in pregnant women who were between sessions, compared to the control group. Although structural changes in the brain were more prominent in the DMN, fronto-parietal brain regions associated with higher-order cognitive tasks (eg, cognitive functions) were also affected.
It is important for new mothers to focus on their baby’s needs and feelings, and to understand their feelings. Accordingly, several studies have indicated a functional change in the DMN. In addition, maternal resting-state functional connectivity was associated with maternal behavior.
The present study speculated that pregnancy-related structural and functional alterations in the DMN alter the neuronal architecture of an individual, thus preparing women for motherhood. Interestingly, it was observed that neuronal changes in the DMN were related to the degree of mother-infant bonding.
Some of the factors that drive pregnancy-related brain plasticity are pregnancy hormones. For example, estradiol levels, particularly in the third trimester, have been associated with changes in brain structure. Sleep, osmotic effects, breastfeeding, stress, or type of delivery have not been linked to any structural or functional changes in the brain during pregnancy. Unexpected exposure to estrogen during late pregnancy has been found to affect pregnancy-related skeletal neuroplasticity.
Analytical data on pregnant women indicated structural and functional plasticity within the DMN, suggesting that mothers experience alterations in the baseline state of the brain. Functional changes in the DMN have been associated with infant-directed processes, while structural changes in the brain are associated with mimicry of preparatory behaviour. In the future, a wide range of potential regulatory factors (such as nutrition, genetic markers, environmental changes, and exercise) must be evaluated to better understand their role in influencing brain processes during pregnancy.