New research from the ESRI has found mothers with higher childcare costs when their child was aged three tended to then work fewer hours when their child was five.
The study was based on 'Growing Up in Ireland' data which tracked the employment of mothers across the first five years of their child's life.
Research professor with the ESRI Helen Russell says many parents face significant childcare costs, especially in urban areas, and that the mothers working life can suffer as a result.
"We found that on average families were spending 12% of their disposable household income on care for their three-year-old and this rose to 16% for lone parents and 20% for low-income households," she said.
"It's quite a substantial burden."