Grandmothers, and not just mothers, may be making an early exit from the workforce to look after children due to soaring childcare costs.
Studies suggest over-55s stepping in to bail out their own children when they become parents may be a factor hindering older women from holding down jobs.
An ESRI study showed older women are five times more likely to leave work early for "care" reasons than men.
It also said research shows "relatives, predominantly grandmothers, provide a significant proportion of childcare in Ireland".
"Caring responsibilities for spouses, grandchildren or others can lead to early exits among older workers, especially if working conditions are incompatible with care," it said.
Women between 50 and 60 are particularly vulnerable to leaving work if they provide more than 10 hours of care a week. These "push factors" to leaving work early are "particularly relevant to the Irish case".
Overall there are 1.1 million women in the labour force, but they represent only 56pc of the female working age population, compared to 68pc of men.
High childcare costs are being blamed, conjuring up images of multi-tasking women juggling a work-life balance after maternity leave only to find high creche fees mean they have to drop the ball. However, the gender gap when it comes to participation rates is most pronounced among those between 45 and 59.
Overall, the number of over- 55s at work has more than doubled in the last decade, from 166,000 in 1998 to 413,000 last year. Some 19pc of the male labour force are over 55, compared with only 12pc of the female labour force.
When it comes to early departures for those in their late 50s, retirement is the number one reason, with job losses, illness and disability next in place, followed by 7pc who left for child or family care reasons.
"We can't say with certainty why older women go," said ESRI author Ivan Privalko.
"But we know these people have been out of work for at least a year and are highly likely to have left the workforce, and women are far more likely to cite the care reason than men."