The typical weekly childcare bill in Northern Ireland is the highest in the UK, trade unionists have said.
A total of £46.50 per week is spent in the region compared with £31 in England.
Families use “substantially” more paid hours than any other region, the Irish Congress of Trade Unions (ICTU) said.
It said increasing women’s access to decent employment should be a key aim of a comprehensive childcare system.
Owen Reidy, ICTU assistant general secretary, said: “We need to start looking at investment in childcare as a vital form of infrastructure, as important for the economy as investment in construction or roads.”
Families in Northern Ireland use substantially more paid hours than any other UK region, a report by the trade unionists said.
At 15 hours, the median number of hours in Northern Ireland is 50% higher than any other UK region.
The median household spends £3.10 per hour and uses 15 hours per week combining for an average weekly spend of £46.50. This compares with £31 in England.
The report added: “This is in addition to the fact that Northern Ireland has the highest proportion of households paying for childcare of any region.
“This means that Northern Ireland households are not only more likely to pay for childcare, but when they do, they are also more likely to use significantly more of it.”
It identified a “motherhood gap” responsible for earnings differences between men and women.
Women with dependent children were overrepresented in part-time employment, compared with men with or without dependent children and women with no dependent children, the report said.
They were also more likely to be in temporary employment and much less likely to be self-employed than men with dependent children, the research showed.
It added: “Having one or more children reduces the female likelihood of being in a permanent, full-time job by almost one-third, with only 45% of females with one or more children working in a permanent, full-time job.”
Fewer than one in three women with no dependent children worked part-time.
This compared with almost one in two women with dependent children who were employed on a part-time basis.