Modelled estimates of annual live births by year ending date.
Official birth estimates from ONS are considered very accurate, but the
lag between the end of the period covered and the publication of
estimates is typically 9-12 months. To gain a more timely indication of
birth trends, the GLA Demography team produces modelled estimates of
annual births based on counts of infants registered with GP practices.
Modelled birth estimates can be produced with the same frequency and
latency that NHS
Digital
publishes patient count data - currently this is monthly and with a lag
of 1-2 weeks.
The approach used to generate the modelled birth estimates was
originally described in this 2016 technical
note.
The methodology relies on the correlation between the count of persons
age 0 (i.e. yet to reach their first birthday) on the patient register
and resident in an area with the number of births that have taken place
in that area over the preceding year.
The data used to create these modelled birth estimates are:
Modelled estimates of patient counts by age, sex, and local
authority of
residence
Official estimates of annual live births by local authority of
residence
A respository of the code used to generate the modelled birth estimates
is available on
GitHub.
The repository's ReadMe provides more information about the methodology
used to produce the estimates as well as a summary analysis of their
past accuracy.
The outputs cover a range of geographies in England.
Within London there is
variation in how annual births are predicted to have changed since the
latest official estimates. The map below shows the percentage change
between the latest official births estimates (01 Jan 2025) and the
latest GLA modelled births estimate (01 Oct 2025) for London Boroughs.
File contents
Files containing the outputs from this modelling process are available
for download below.
The downloads contain official ONS annual births estimates between 01
Jul 1992 and 01 Jan 2025, interpolated estimates at monthly intervals
between official estimates, and predictions of annual births up to 01
Oct 2025. Predicted data are given alongside the upper and lower bounds
of the 95% prediction interval.
The data are given for local authority districts, regions, country, and
international territorial levels ITL2 in England.
These data are not currently split by sex.
The following are example rows to show the format of the csv data file
downloads.
actual_and_predicted_births.csv
gss_code
gss_name
geography
sex
date
type
annual_births
interval_lower
interval_upper
…
…
…
…
…
…
…
…
…
E09000028
Southwark
LAD23
persons
2024-12-01
interpolated
3298.9
NA
NA
E09000028
Southwark
LAD23
persons
2025-01-01
actual
3256
NA
NA
E09000028
Southwark
LAD23
persons
2025-02-01
predicted
3287.8
3202.7
3373
…
…
…
…
…
…
…
…
…
E09000028
Southwark
LAD23
persons
2025-10-01
predicted
3184
3102
3265.9
birth_gp_ratios.csv
gss_code
gss_name
geography
sex
date
ratio
ratio_lower
ratio_upper
ratio_type
gp_count
actual_births
…
…
…
…
…
…
…
…
…
…
…
E09000028
Southwark
LAD23
persons
2024-12-01
1.065
NA
NA
interpolated
3098.2
NA
E09000028
Southwark
LAD23
persons
2025-01-01
1.066
NA
NA
actual
3054.5
3256
E09000028
Southwark
LAD23
persons
2025-02-01
1.068
1.04
1.096
predicted
3078.6
NA
…
…
…
…
…
…
…
…
…
…
…
E09000028
Southwark
LAD23
persons
2027-07-01
1.063
1.034
1.091
predicted
NA
NA
The plots.zip download contains png files of plots showing the actual
and predicted annual births for each geographic area in the same format
as the actual and predicted annual live births plot for London above.
There are 3 plots for each different area which give different starting
dates for the official estimates backseries to span a total of either 5,
10 or 15 years.