About this data

Source: Office for National Statistics (ONS), Births in England and Wales: 2025

• The standardised mean age adjusts for changes in the number of women at each age, so it isn't affected by changes in the population's age structure.
• First births are a woman's first live-born child, whether or not she was married. Before 2012, ONS estimated this birth order for births outside marriage, because it wasn't recorded at registration.

This chart appears in Births and fertility rates.