Brain region increases after giving birth

A tiny region of the brain responsible for our emotional responses increases in size during the first few weeks after giving birth, a new study has found.

Associate Professor Eileen Lueders

An international research team, including Associate Professor Eileen Lueders and Dr Florian Kurth from the University of Auckland, studied brain changes in women after they gave birth.

The team focused on the amygdala, an almond-shaped and small region of the brain located deep within the left and right temporal lobe and known for its involvement in the processing and regulation of emotions.

The study included 14 healthy women aged between 25 and 38 years of age who had normal pregnancies and uncomplicated deliveries. For half of the women it was a first-time birth.

Measuring the amygdala at two time points – right after giving birth and about five weeks later – revealed the amygdala increases, especially in a subregion referred to as superficial area.

Since this particular area is known to be a major moderator of social behaviour, its enlargement after giving birth may be the result of - or a cause for - the special attachment that forms between a mother and her newborn.

This could be because the superficial area relays olfactory input (smell). Smell is instrumental in social functioning across all life stages, but could play a particularly important role postpartum, for example when the mother starts communicating and bonding with her baby.

“These findings are exciting and add to a growing body of research suggesting that giving birth is associated with a gain of brain tissue” says Dr Lueders. “Other studies have reported a loss of brain tissue during pregnancy, so tissue gain after pregnancy is great news for all mothers.

“The anatomical changes occurring within weeks of giving birth may reflect clever adaptations of a mother’s brain tuning into the distinct and ever-changing needs of a newborn. The research also demonstrates that our brains are highly plastic, even in adulthood.”

Dr Kurth says that further research should also focus on several months or even years into motherhood as well as before pregnancy.

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