Brain tissue increases after giving birth - study

A new study has found that grey matter in women’s brains increases after they give birth.

Eileen Lueders

An international research team, including Associate Professor Eileen Lueders and Dr Florian Kurth from the University of Auckland, analysed MRI brain scans of 14 pregnant women at two time points – firstly between one and two days after childbirth and again at four to six weeks after childbirth.

When scans were compared between those two time points, researchers found a marked increase in grey matter in both cortical and sub-cortical regions, across both hemispheres and in all four brain lobes.

Grey matter comprises the nerve cells in our brains responsible for processing information and as such, contributes to thinking, feeling, and behaviour.

Study participants were 25–38 years of age and for half the women it was a first-time birth. All had normal pregnancies and uncomplicated deliveries and were breastfeeding at the time of the second brain scan.

Study lead author Associate Professor Lueders says the observed grey matter changes add further evidence that the human brain is highly plastic, even in adulthood. While the findings are significant, further research is needed to understand whether the tissue increase is an effect of brain restoration or reorganisation, or both.

“The brain may simply recover from the tissue loss that occurred during pregnancy, so what we see could be merely a restoration effect.

“However, at the same time, our findings may also point to actual brain enhancement: being a mother requires a whole new repertoire of skills and behaviour, and research has shown that exercising new skills and engaging in new activities leads to tissue increases.

“So, mothers might not just get back what they lost during pregnancy, but even gain a bit more.”

Research into the effects of pregnancy and birth on the human brain is sparse with only five current studies having assessed structural changes in the mother’s brain after giving birth.

Co-author Professor Inger Sundström Poromaa, from the Department of Women’s and Children’s Health at Sweden’s Uppsala University, adds that future studies will have to tackle the role of sleep deprivation and consider additional variables such as the effects of breastfeeding and prior pregnancies after childbirth.

The study is published in science journal Cortex.

Media contact

Anne Beston | Media adviser
DDI 09 923 3258
Mob 021 970 089