New data from the Economic and Social Research Institute shows that over 76,000 births were registered in 2009, giving the country the highest birth rate of any country in the EU per head of population.
The Irish Total Period Fertility Rate increased from an average of 1.9 in 2000 to 2.1 in 2009.
France was just behind Ireland with a rate of 2.0 while Hungary, Latvia and Portugal had the lowest rates that year.
The ESRI says the fertility rate now stands at a level required for the long-term replacement of the population in the absence of any net inward migration.
The report also says 2009 saw a further decline in the number of stillbirths and neonatal deaths.
Over a quarter of babies were delivered by caesarean section - a 25% increase since the turn of the century and the average birth weight was 3.46kg (7lbs 6oz).
The ESRI says almost 24% of the births were to mothers born outside Ireland.
Over 45% of babies were reported to be exclusively breastfed when they were discharged from hospital.
In the 12 months covered by the report, the average age of women giving birth was 31.3 years, 27% of births were to women over the age of 35 and 3% to women aged 19 or less.
There were 148 home births attended by independent domiciliary midwives in 2009 compared with 216 in 2000.
The National Perinatal Reporting System is used to log every birth in the country.
It lists the social and biological characteristics of all mothers giving birth and all babies born in Ireland.