New figures from the ESRI show that Ireland has the highest birth rate of any of the 27 European Union countries.
Over 74,000 babies were born in the country last year, representing a slight fall at 16 births per 1,000 of population.
The Perinatal Statistics Report 2011 also shows a 27% reduction in the number of babies who died during or shortly after birth over the past nine years.
About 33% of last year's newborns were to single mothers, while 40% were to first-time mothers with an average age of 29.
Almost 24% of births in 2011 were to mothers born outside of Ireland.
The ESRI also found only 40% of Irish mothers are exclusively breastfeeding, compared to 75% for babies born to mothers from mainland Europe and Australia.