Revealed: The average age mothers in Ireland give birth to their first child
Two-thirds of babies in Ireland are born to mothers aged in their 30s
Further education and the cost of living are among the reasons why 65pc of babies are being born to mothers aged between 30 and 39.
New Central Statistics Office data revealed that on average, mothers are giving birth to their first child at almost 31 years of age.
Three decades ago, women were almost five years younger when they had their first baby.
Meanwhile, more than 23,000 children born last year were out of wedlock, according to the CSO's 'Statistical Yearbook of 2017'. The statistics track everything from births and marriages to crime and potato farming.
Cliona Loughnane of the Women's Council of Ireland (WCI) said the rising age of mothers followed decisions made by women and by families in modern Ireland.
"It's about when it's right for a woman to have a child," Ms Loughnane said. "It's a gradual increase [in age] and Ireland is following a general trend that is happening around Europe.
"Part of that is higher education attainment, so that will probably delay when women decide to have a family."
Ms Loughnane added that women may also be considering their careers before settling down with a family. However, she said it was often a decision made by a couple, and not just the woman.
Elsewhere, the data revealed that homeowners are spending almost three times as much of their weekly income on rent and mortgages than they did in the 1980s.
In 1980 just over 7pc was spent on housing costs.
However, this jumped to 18.2pc in 2010 and rose again to 19.6pc in 2016. Housing expert at Dublin Institute of Technology Dr Lorcan Sirr said the lack of supply was one of the biggest factors in this upsurge in cost.
"The big issue is that our population has increased significantly since 1980 - over a million - and yet we haven't had an increase near that in the number of houses, so it doesn't go," he said.
Dr Sirr added that the wages of workers had not kept up with the rise in cost of housing, particularly with the commercialisation of the housing market.
He said the number of council houses had dropped significantly in that period, while mortgages from banks come at a much higher cost than a council or a building society.
Meanwhile, the proportion of income being spent by homeowners on food has been slashed in half in the same period, from 27.7pc to 14.7pc.
Dermott Jewell of the Consumers' Association of Ireland told the Irish Independent that the influx of supermarkets and frequency of weekly and fortnightly bulk shopping had contributed to this drop.
He said shopping locally on a daily basis was much more prominent 30 years ago.
"That was a time when we did not have an Aldi or a Lidl, supermarkets which are cheaper right across the board," Mr Jewell said.
"There has been a change in how the price index works.
"The habit (in the 1980s) was not to go to a supermarket on a weekly or monthly basis. It (shopping daily) was only for convenience but it was not going to do anything for your budget."
Other notable statistics include that more than 1,000 same-sex marriages were recorded in 2016.
The county with the lowest number recorded was Roscommon, with two same-sex marriages in the year.
The Roscommon-South Leitrim constituency was the only one to vote 'no' in the 2015 marriage referendum.