Mother's weight gain between initial assessment and birth, by BMI group at initial assessment and local health board
Standard shorthand is used in this table: [x] = not available.
| Data values | Data description | Year | Area | Mothers weight gain | BMI group |
|---|---|---|---|---|---|
| 158 | Number | 2024 | Wales | Women who gained less than the recommended amount of weight | BMI above 10 and below 18.5 |
| 2,442 | Number | 2024 | Wales | Women who gained less than the recommended amount of weight | BMI above 18.5 and below 25 |
| 1,158 | Number | 2024 | Wales | Women who gained less than the recommended amount of weight | BMI above 25 and below 30 |
| 1,586 | Number | 2024 | Wales | Women who gained less than the recommended amount of weight | BMI of 30 and over |
| 66 | Number | 2024 | Wales | Women who gained the recommended amount of weight | BMI above 10 and below 18.5 |
| 1,264 | Number | 2024 | Wales | Women who gained the recommended amount of weight | BMI above 18.5 and below 25 |
| 985 | Number | 2024 | Wales | Women who gained the recommended amount of weight | BMI above 25 and below 30 |
| 1,030 | Number | 2024 | Wales | Women who gained the recommended amount of weight | BMI of 30 and over |
| 35 | Number | 2024 | Wales | Women who gained more than the recommended amount of weight | BMI above 10 and below 18.5 |
| 696 | Number | 2024 | Wales | Women who gained more than the recommended amount of weight | BMI above 18.5 and below 25 |
| 1,410 | Number | 2024 | Wales | Women who gained more than the recommended amount of weight | BMI above 25 and below 30 |
| 1,397 | Number | 2024 | Wales | Women who gained more than the recommended amount of weight | BMI of 30 and over |
| 55 | Number | 2024 | Betsi Cadwaladr University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 10 and below 18.5 |
| 701 | Number | 2024 | Betsi Cadwaladr University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 18.5 and below 25 |
| 300 | Number | 2024 | Betsi Cadwaladr University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 25 and below 30 |
| 477 | Number | 2024 | Betsi Cadwaladr University Local Health Board | Women who gained less than the recommended amount of weight | BMI of 30 and over |
| 36 | Number | 2024 | Betsi Cadwaladr University Local Health Board | Women who gained the recommended amount of weight | BMI above 10 and below 18.5 |
| 508 | Number | 2024 | Betsi Cadwaladr University Local Health Board | Women who gained the recommended amount of weight | BMI above 18.5 and below 25 |
| 336 | Number | 2024 | Betsi Cadwaladr University Local Health Board | Women who gained the recommended amount of weight | BMI above 25 and below 30 |
| 350 | Number | 2024 | Betsi Cadwaladr University Local Health Board | Women who gained the recommended amount of weight | BMI of 30 and over |
| 23 | Number | 2024 | Betsi Cadwaladr University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 10 and below 18.5 |
| 320 | Number | 2024 | Betsi Cadwaladr University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 18.5 and below 25 |
| 585 | Number | 2024 | Betsi Cadwaladr University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 25 and below 30 |
| 537 | Number | 2024 | Betsi Cadwaladr University Local Health Board | Women who gained more than the recommended amount of weight | BMI of 30 and over |
| 2 | Number | 2024 | Powys Teaching Local Health Board | Women who gained less than the recommended amount of weight | BMI above 10 and below 18.5 |
| 21 | Number | 2024 | Powys Teaching Local Health Board | Women who gained less than the recommended amount of weight | BMI above 18.5 and below 25 |
| 5 | Number | 2024 | Powys Teaching Local Health Board | Women who gained less than the recommended amount of weight | BMI above 25 and below 30 |
| 4 | Number | 2024 | Powys Teaching Local Health Board | Women who gained less than the recommended amount of weight | BMI of 30 and over |
| 1 | Number | 2024 | Powys Teaching Local Health Board | Women who gained the recommended amount of weight | BMI above 10 and below 18.5 |
| 22 | Number | 2024 | Powys Teaching Local Health Board | Women who gained the recommended amount of weight | BMI above 18.5 and below 25 |
| 12 | Number | 2024 | Powys Teaching Local Health Board | Women who gained the recommended amount of weight | BMI above 25 and below 30 |
| 3 | Number | 2024 | Powys Teaching Local Health Board | Women who gained the recommended amount of weight | BMI of 30 and over |
| 0 | Number | 2024 | Powys Teaching Local Health Board | Women who gained more than the recommended amount of weight | BMI above 10 and below 18.5 |
| 15 | Number | 2024 | Powys Teaching Local Health Board | Women who gained more than the recommended amount of weight | BMI above 18.5 and below 25 |
| 11 | Number | 2024 | Powys Teaching Local Health Board | Women who gained more than the recommended amount of weight | BMI above 25 and below 30 |
| 5 | Number | 2024 | Powys Teaching Local Health Board | Women who gained more than the recommended amount of weight | BMI of 30 and over |
| 21 | Number | 2024 | Hywel Dda University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 10 and below 18.5 |
| 266 | Number | 2024 | Hywel Dda University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 18.5 and below 25 |
| 108 | Number | 2024 | Hywel Dda University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 25 and below 30 |
| 196 | Number | 2024 | Hywel Dda University Local Health Board | Women who gained less than the recommended amount of weight | BMI of 30 and over |
| 7 | Number | 2024 | Hywel Dda University Local Health Board | Women who gained the recommended amount of weight | BMI above 10 and below 18.5 |
| 200 | Number | 2024 | Hywel Dda University Local Health Board | Women who gained the recommended amount of weight | BMI above 18.5 and below 25 |
| 136 | Number | 2024 | Hywel Dda University Local Health Board | Women who gained the recommended amount of weight | BMI above 25 and below 30 |
| 145 | Number | 2024 | Hywel Dda University Local Health Board | Women who gained the recommended amount of weight | BMI of 30 and over |
| 9 | Number | 2024 | Hywel Dda University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 10 and below 18.5 |
| 127 | Number | 2024 | Hywel Dda University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 18.5 and below 25 |
| 208 | Number | 2024 | Hywel Dda University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 25 and below 30 |
| 217 | Number | 2024 | Hywel Dda University Local Health Board | Women who gained more than the recommended amount of weight | BMI of 30 and over |
| [x] | Number | 2024 | Swansea Bay University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 10 and below 18.5 |
| [x] | Number | 2024 | Swansea Bay University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 18.5 and below 25 |
| [x] | Number | 2024 | Swansea Bay University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 25 and below 30 |
| [x] | Number | 2024 | Swansea Bay University Local Health Board | Women who gained less than the recommended amount of weight | BMI of 30 and over |
| [x] | Number | 2024 | Swansea Bay University Local Health Board | Women who gained the recommended amount of weight | BMI above 10 and below 18.5 |
| [x] | Number | 2024 | Swansea Bay University Local Health Board | Women who gained the recommended amount of weight | BMI above 18.5 and below 25 |
| [x] | Number | 2024 | Swansea Bay University Local Health Board | Women who gained the recommended amount of weight | BMI above 25 and below 30 |
| [x] | Number | 2024 | Swansea Bay University Local Health Board | Women who gained the recommended amount of weight | BMI of 30 and over |
| [x] | Number | 2024 | Swansea Bay University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 10 and below 18.5 |
| [x] | Number | 2024 | Swansea Bay University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 18.5 and below 25 |
| [x] | Number | 2024 | Swansea Bay University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 25 and below 30 |
| [x] | Number | 2024 | Swansea Bay University Local Health Board | Women who gained more than the recommended amount of weight | BMI of 30 and over |
| 21 | Number | 2024 | Cwm Taf Morgannwg University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 10 and below 18.5 |
| 286 | Number | 2024 | Cwm Taf Morgannwg University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 18.5 and below 25 |
| 107 | Number | 2024 | Cwm Taf Morgannwg University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 25 and below 30 |
| 255 | Number | 2024 | Cwm Taf Morgannwg University Local Health Board | Women who gained less than the recommended amount of weight | BMI of 30 and over |
| 6 | Number | 2024 | Cwm Taf Morgannwg University Local Health Board | Women who gained the recommended amount of weight | BMI above 10 and below 18.5 |
| 195 | Number | 2024 | Cwm Taf Morgannwg University Local Health Board | Women who gained the recommended amount of weight | BMI above 18.5 and below 25 |
| 179 | Number | 2024 | Cwm Taf Morgannwg University Local Health Board | Women who gained the recommended amount of weight | BMI above 25 and below 30 |
| 261 | Number | 2024 | Cwm Taf Morgannwg University Local Health Board | Women who gained the recommended amount of weight | BMI of 30 and over |
| 1 | Number | 2024 | Cwm Taf Morgannwg University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 10 and below 18.5 |
| 111 | Number | 2024 | Cwm Taf Morgannwg University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 18.5 and below 25 |
| 250 | Number | 2024 | Cwm Taf Morgannwg University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 25 and below 30 |
| 317 | Number | 2024 | Cwm Taf Morgannwg University Local Health Board | Women who gained more than the recommended amount of weight | BMI of 30 and over |
| [x] | Number | 2024 | Aneurin Bevan University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 10 and below 18.5 |
| [x] | Number | 2024 | Aneurin Bevan University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 18.5 and below 25 |
| [x] | Number | 2024 | Aneurin Bevan University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 25 and below 30 |
| [x] | Number | 2024 | Aneurin Bevan University Local Health Board | Women who gained less than the recommended amount of weight | BMI of 30 and over |
| [x] | Number | 2024 | Aneurin Bevan University Local Health Board | Women who gained the recommended amount of weight | BMI above 10 and below 18.5 |
| [x] | Number | 2024 | Aneurin Bevan University Local Health Board | Women who gained the recommended amount of weight | BMI above 18.5 and below 25 |
| [x] | Number | 2024 | Aneurin Bevan University Local Health Board | Women who gained the recommended amount of weight | BMI above 25 and below 30 |
| [x] | Number | 2024 | Aneurin Bevan University Local Health Board | Women who gained the recommended amount of weight | BMI of 30 and over |
| [x] | Number | 2024 | Aneurin Bevan University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 10 and below 18.5 |
| [x] | Number | 2024 | Aneurin Bevan University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 18.5 and below 25 |
| [x] | Number | 2024 | Aneurin Bevan University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 25 and below 30 |
| [x] | Number | 2024 | Aneurin Bevan University Local Health Board | Women who gained more than the recommended amount of weight | BMI of 30 and over |
| 59 | Number | 2024 | Cardiff and Vale University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 10 and below 18.5 |
| 1,168 | Number | 2024 | Cardiff and Vale University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 18.5 and below 25 |
| 638 | Number | 2024 | Cardiff and Vale University Local Health Board | Women who gained less than the recommended amount of weight | BMI above 25 and below 30 |
| 654 | Number | 2024 | Cardiff and Vale University Local Health Board | Women who gained less than the recommended amount of weight | BMI of 30 and over |
| 16 | Number | 2024 | Cardiff and Vale University Local Health Board | Women who gained the recommended amount of weight | BMI above 10 and below 18.5 |
| 339 | Number | 2024 | Cardiff and Vale University Local Health Board | Women who gained the recommended amount of weight | BMI above 18.5 and below 25 |
| 322 | Number | 2024 | Cardiff and Vale University Local Health Board | Women who gained the recommended amount of weight | BMI above 25 and below 30 |
| 271 | Number | 2024 | Cardiff and Vale University Local Health Board | Women who gained the recommended amount of weight | BMI of 30 and over |
| 2 | Number | 2024 | Cardiff and Vale University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 10 and below 18.5 |
| 123 | Number | 2024 | Cardiff and Vale University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 18.5 and below 25 |
| 356 | Number | 2024 | Cardiff and Vale University Local Health Board | Women who gained more than the recommended amount of weight | BMI above 25 and below 30 |
| 321 | Number | 2024 | Cardiff and Vale University Local Health Board | Women who gained more than the recommended amount of weight | BMI of 30 and over |
| 196 | Number | 2023 | Wales | Women who gained less than the recommended amount of weight | BMI above 10 and below 18.5 |
| 2,996 | Number | 2023 | Wales | Women who gained less than the recommended amount of weight | BMI above 18.5 and below 25 |
| 1,389 | Number | 2023 | Wales | Women who gained less than the recommended amount of weight | BMI above 25 and below 30 |
| 1,728 | Number | 2023 | Wales | Women who gained less than the recommended amount of weight | BMI of 30 and over |
Next update expected:August 2026
Updates
- 19th December 2025
- Dataset first published.
Main information
- Designation
- Accredited official statistics
- Data provider
- Digital Health and Care Wales (DHCW)
- Data source
- Maternity Indicators Dataset (MIDS)
Overview
- Summary of dataset and variables
Number and percentage of mother's weight gain between initial assessment and birth, by BMI group, broken down by local health board.
This data is derived from the Maternity Indicators dataset, provided to the Welsh Government by Digital Health and Care Wales (DHCW).
The Maternity Indicators dataset combines records from a mother’s initial assessment with a child’s birth record Full details of every data item available in the Maternity Indicators dataset are available through the NHS Wales Data Dictionary.
- Data collection or calculation
Data from the Maternity Indicators dataset only includes initial assessment data where the initial assessment and birth both occurred in the same health board, in Wales only.
Data should include all hospital births and some home births; however, due to the way data is recorded, we are unable to distinguish between home and hospital births in some health boards. Births to Welsh resident mothers who gave birth in England or in any other country outside of Wales are not included in the data.
Data for each calendar year refers to when the baby was born for both birth and initial assessment statistics. Initial assessments may have taken place in the previous year but would be counted in the year in which the birth occurred. This ensures data throughout a single pregnancy is recorded in the same year.
The Wales-level percentage for pregnant women with BMI of 30 or greater are based on all records minus records with a ‘not stated’ or invalid value.
Records where BMI, height or weight are unrealistic values are classed as invalid, for example where BMI is less than 10 or greater than 100; where the pregnant woman’s weight is less than 30kg or more than 250kg; and where the pregnant woman’s height was less than 120cm or greater than 200cm.
The calculation also only includes women who had their initial assessment at 14 completed weeks of pregnancy or earlier. This is to reduce unfair comparisons where the BMI calculation is affected by baby growth where the initial assessment happened after 15 weeks. Between 11% to 15% of all pregnancies have been excluded for this reason in each year.
The number of records excluded can be found in Table 4 of the Maternity and birth statistics: quality report tables.
The calculation also only includes women who had their initial assessment at 14 completed weeks of pregnancy or earlier. This is to reduce unfair comparisons where the BMI calculation is affected by baby growth where the initial assessment happened after 15 weeks. Between 11% to 15% of all pregnancies have been excluded for this reason in each year.
- Statistical quality
For BMI, more than 90% of records had valid data for both height and weight data items, across all health boards, in most years apart from: Cwm Taf in 2016 (77%) and in 2019 (88%); and Betsi Cadwaladr in 2019 (89%).
In 2024, Aneurin Bevan has been excluded from analysis due to high levels of invalid data for height leading to 77% missing data for BMI. Data for Wales represents the 6 remaining health boards.
From 1st April 2019 health service provision for residents of Bridgend local authority moved from Abertawe Bro Morgannwg to Cwm Taf. The health board names changed to Cwm Taf Morgannwg University Health Board and Swansea Bay University Health Board. Data for Abertawe Bro Morgannwg and Cwm Taf are available for previous years in this table. More detailed information on the sources of data and analyses in this statistical release are provided in the quality report.
Published by
- Organisation
- Welsh Government
- Contact email
- stats.healthinfo@gov.wales