Winter babies at 'higher risk of mental disorders'

New research has revealed that babies born in winter are at higher risk of developing mental health disorders.

Researchers at Cardiff University have found that cortisol levels, a stress hormone, are higher in women who give birth in autumn and winter than in those who give birth in the spring or summer.

Cortisol levels naturally increase during pregnancy, said Professor Ros John.

"Our data show that fall and winter babies are exposed to particularly high levels just before they are born.

Professor John said, "On average, women who give birth in the fall or winter had 20% more salivary cortisol just before delivery than those who give birth in the spring or summer.

"Since high levels of cortisol in pregnant women were previously badociated with a higher risk of developing mental health disorders in children, the new discoveries could explain why these disorders are more common in people born during the months of ## 147 ## 39; winter.

"However, they do not explain why women who give birth in winter or fall have these higher levels of cortisol."

The researchers investigated the relationship between seasonal and salivary cortisol levels, depression, and anxiety symptoms in pregnant women living in South Wales.

The team discovered a link between seasonal and salivary cortisol term concentrations in the study, which involved 316 women.

The university said the data had been collected at pre-surgical appointments and immediately after birth, through a questionnaire and notes recorded by the midwife research.