The number of registered births in the State has fallen by almost 18 per cent in the last decade, according to Central Statistics Office (CSO) data.A total of 65,909 births were registered in 2015, but this fell to 54,125 last year, according to the CSO’s Vital Statistics Yearly Summary for 2025. However, there was a small increase (63) in the number of births between 2024 and last year.The figure for last year represented an annual birth rate of 9.9 per 1,000 of population, down from 14.1 per 1,000 of population in 2015. In the same time period, the fertility rate has dropped sharply, from 1.9 in 2015 to 1.5 in 2025. A value of 2.1 is usually considered to be the level at which the population would replace itself in the long run, ignoring migration.The average age of first-time mothers increased by 1.1 years, rising from 30.7 years in 2015 to 31.8 years in 2025.The average age of a mother giving birth last year was 33.3 years, unchanged from 2024. In 2015, this figure was 32.5 years and it was 31 years in 2005. [ Postponing parenthood: How Ireland’s housing crisis is forcing people to delay having childrenOpens in new window ]The CSO said 35,587 deaths were registered last year, a year-on-year increase of 414. Of the deaths registered, 18,763 were men and 16,824 were women.The annual death rate stood at 6.5 per 1,000 of population last year, up from 6.4 per 1,000 in 2015 but down on the rate of 6.6 per 1,000 recorded in 2005.More than a third (36.4 per cent) of registered deaths last year were of people aged 85 years and over. People aged 65 and over accounted for 83 per cent of all deaths. The main causes of death were malignant neoplasms such as cancerous tumours (29.8 per cent) or diseases of the circulatory system (26.9 per cent). Deaths due to accidents, suicide and other external causes accounted for 4.3 per cent of registered deaths.There were just 20 deaths among children aged one to four years, accounting for just 0.1 per cent of the total figure.A further 161 infant deaths were registered, giving an infant mortality rate of three deaths per 1,000 live births. An infant death is categorised as the death of a live-born infant under the age of one.There were 124 neonatal deaths registered in 2025, giving a neonatal mortality rate of 2.3 deaths per 1,000 live births. Neonatal deaths are deaths of infants aged under four weeks. Both the infant mortality rate and neonatal mortality rate declined from 2024, when they were 3.6 and 2.7 respectively.There were 19,898 marriages registered last year, of which 624 were same-sex marriages.The marriage rate last year was 3.6 per 1,000 of population, down from 4.8 marriages per 1,000 in 2015.The CSO notes that not all life events registered in a year occur in that particular year.