It may surprise new mothers fighting the effects of "baby brain" and sleepless nights. Picture: AP

London - It may surprise new mothers fighting the effects of "baby brain" and sleepless nights.

But having children may make women mentally sharper in later life, a study suggests.

They have "younger" brains than women who have never had children, based on the MRI scans of more than 12 000 patients.

Even in middle age, their brains are up to six months younger, and having more children, up to five, appears to be better for grey matter. Experts believe that mothers may benefit from oestrogen, the hormone which is produced in pregnancy, or have a boost to their immune system from carrying a child.

"When you look at factors which affect how we age, having children appears to make a difference," said Dr Ann-Marie de Lange, first author of the study from the University of Oslo.

"Women who have children may benefit from positive effects later in life, which may arise because hormones or immune factors related to pregnancy and childbirth have a protective effect against brain ageing."

The study uses brain scans of middle-aged women, with an average age of 54, who were part of the UK Biobank genetic study. More than 9 500 were mothers.

Researchers analysed their brains based on their total grey matter and volume, including in areas important for memory, such as the hippocampus.

They found mothers’ brains were around six months younger biologically than those of non-mothers, which may reflect long-term brain changes caused by pregnancy or by the demands of bringing up a child.

The study is in the journal Proceedings of the National Academy of Sciences.

Daily Mail