CSO statistics released today showed some 70,620 babies were born in 2007, the highest number since 1982.
Around 33 per cent were delivered outside marriage and just over half of those births were to cohabiting parents. Almost a third of all women who gave birth and who were not married were aged over 30.
More than 210 schoolgirls below the age of consent - 17 - gave birth last year, while a further 148 newborns were delivered to 16 year olds.
The statistics also reveal one of 65 girls aged 15 or under was married when she became a mother, while eight others were living with a partner.
The CSO also reported that the fertility rate also rose slightly last year, with women having more than two children for the first time in 16 years. Overall, one in nine women aged in their 30s and one in 15 in their 20s had a baby.
Elsewhere, the CSO vital statistics yearly summary recorded 28,050 deaths in 2007, with more than three in every four from either cardiovascular disease (35 per cent), cancer (28 per cent), or disease of the respiratory system (13 per cent).
The infant death rate halved over the last decade with 221 babies under the age of one dying.
A total of 460 suicides were also recorded, with four times more men than women taking their own lives.
In 2007, there were 22,544 marriages registered during the year, with 3,684 divorces granted by the courts, 1,185 separations registered, and 28 marriages annulled.
The State's population stood at 4.3 million.
PA