Pregnancy found to cause changes in brain, study suggests

A study published in Nature Neuroscience has found that pregnancy can cause a reduction in grey matter in specific parts of a woman’s brain, which improve bonding between mother and baby and help prepare for the demands of motherhood.

The research examined the brain scans of women before they became pregnant, soon after they gave birth, and two years later, to see how the brain changed. The findings indicated ‘substantial’ reductions in the volume of grey matter in the brains of first-time mothers.

Grey matter in the central nervous system consists of neuronal cell bodies and includes regions of the brain involved in muscle control, and sensory perception such as seeing and hearing, memory, emotions, speech, decision making, and self-control.

The researchers reasoned that the reduction of grey matter would give new mothers an advantage by helping them recognise the needs of their child, be more aware of potential social threats and become more attached to their baby.

Elseline Hoekzema, study author and postdoctoral researcher at the Institute of Psychology at Leiden University in the Netherlands, commented: "We can speculate that the volume reductions observed in pregnancy represent a process of specialisation or further maturation of this Theory of Mind network that, in some way, serves an adaptive purpose for pending motherhood."