- The fertility rate is a measure of the annual number of births to women of a specified age or age group per 1,000 women in that age group. The chart shows the age-specific fertility rates for calendar years between 1938 and 2019.
- The rates for women under 20, as well as those aged 40 and over, are based on the female populations aged 15 to 19 and 40 to 44, respectively.
- Age-specific fertility rates for 1981 are based on a 10% sample due to the late submission of some birth registrations.
- The population estimates used to calculate fertility rates from 1938 to 1980 are rounded to the nearest hundred and are therefore of a slightly lower level of accuracy than the fertility rates for 1981 onwards.
For further detail on methodology access the ONS user guide to birth statistics