Pregnancy and motherhood are associated with neural adaptations that help prepare women for caregiving. A new study suggests that certain aspects of the emotional bond with the baby before birth are already reflected in maternal brain activity.

Pregnancy is a period of change and adaptation, characterised by psychological and neurobiological changes associated with the transition to motherhood and the development of caregiving behaviours. One of the central aspects of this process is maternal-fetal attachment (MFA), the emotional bond between a pregnant woman and her unborn baby, reflected in her thoughts, feelings, and behaviours towards the fetus.

MFA is a multidimensional phenomenon, ranging from the pregnant woman’s attention to changes in her body and fetal movements to interactions with the fetus, the ability to imagine the baby and anticipate life together, and the motivation to adopt behaviours that promote the baby’s health and well-being.

Previous research suggests that higher levels of maternal-fetal attachment during pregnancy are associated with stronger postnatal bonding, more sensitive maternal behaviour, and more responsive mother-infant interactions after birth. However, despite decades of research on MFA, its neurobiological basis remains poorly understood.

Against this backdrop, Kathy Ayala and Helena Rutherford from Yale University, USA, with their colleagues conducted a study, supported by the Bial Foundation, involving 35 women in their third trimester of pregnancy (mean gestational age: 36.8 weeks). Participants underwent a resting-state electroencephalogram (EEG). From these recordings, the researchers analysed brain signal coherence, a well-established measure of connectivity between regions of the cortex that has been associated with cognitive, attentional, and emotional processes relevant to parenting.

Using the EEG data, the researchers calculated alpha-band coherence across intra-frontal, intra-parietal, and frontoparietal regions. This measure provides an estimate of the extent to which activity in different brain regions occurs in a coordinated manner. Maternal-fetal attachment was assessed using the Prenatal Attachment Inventory-Revised (PAI-R), which comprises three dimensions: anticipation, interaction, and differentiation.

The findings, published in the article Bonding before birth: Maternal–fetal attachment and maternal cortical connectivity in late pregnancy in the Journal of Neuroendocrinology, showed that increased left frontoparietal and intra-frontal alpha coherence was associated with higher scores on the anticipation and interaction subscales of the PAI-R. In other words, pregnant women who more frequently imagined their baby, anticipated life together, and engaged more with the fetus also showed greater coordination of activity between specific brain regions. These associations remained even after accounting for gestational age and parity, that is, whether or not the woman had previously given birth.

These findings suggest that individual differences in cortical connectivity are associated with MFA, particularly the anticipatory and interactional aspects of the pregnant woman’s psychological engagement with the fetus. Identifying these neural associations suggests that some processes related to maternal-fetal attachment may be reflected in brain connectivity during pregnancy, contributing to a better understanding of the neurobiological basis of this early bond.

“Our study suggests that individual differences in maternal brain connectivity are associated with specific aspects of the emotional bond with the fetus, offering new insights into the neurobiological basis of this early relationship between mother and child”, says Helena Rutherford.

Learn more about the project “111/16 - A psychophysiological perspective of the transformative experience of pregnancy” here.