Childcare helps to reduce stress among children whose working mothers are in jobs with low satisfaction, according to a study.
It found children who spent more time in childcare were protected from mothers' emotional exhaustion.
Dr Julie Turner-Cobb of Bath University and Dr David Jessop at Bristol University carried out the research.
"It can help protect children from the effects of their mother's low job quality," said Dr Turner-Cobb.
"Ensuring that mothers of young children have good support in the workplace is essential for supporting both mothers and their children," she said.
The findings are based on tests recording levels of the stress hormone cortisol.
Researchers took saliva samples in the morning and evening from 56 children aged three to four-years-old.
They also surveyed mothers about their workplace conditions and home life over six months.
When levels of the hormone remain high or become disrupted in some way over a prolonged period of time they may have consequences for health.