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Welsh Government
Data Provider: Welsh Government Number and percentage of women who 'stopped smoking' during pregnancy, by health board providing the service
None
Year[Filtered]
Measure1
Status[Filter]
Area[Filtered]
Click here to sortTotal womenClick here to sortNumber of women with valid smoking status at initial assessment AND birthClick here to sortNumber of women smoking at initial assessmentClick here to sortNumber of women smoking at initial assessment but not at birthClick here to sortPercentage of women who 'stopped smoking'Click here to sortPercentage of women with complete data
WalesWales percentage excludes data from Hywel Dda and Swansea Bay in 2021-2023, and Swansea Bay in 2024, because of their low reliability. See notes.21,67320,9442,71846317.096.6
Betsi Cadwaladr5,1535,11091614916.399.2
Powys17516014214.391.4
Hywel Dda2,6602,48425500.093.4
Swansea BayxNot available - Between 2021 and 2024, Swansea Bay submitted a very high number of records for ‘not smoking\’ at birth, which is likely to be an error so data for this health board has been excluded.xNot available - Between 2021 and 2024, Swansea Bay submitted a very high number of records for ‘not smoking\’ at birth, which is likely to be an error so data for this health board has been excluded.xNot available - Between 2021 and 2024, Swansea Bay submitted a very high number of records for ‘not smoking\’ at birth, which is likely to be an error so data for this health board has been excluded.xNot available - Between 2021 and 2024, Swansea Bay submitted a very high number of records for ‘not smoking\’ at birth, which is likely to be an error so data for this health board has been excluded.xNot available - Between 2021 and 2024, Swansea Bay submitted a very high number of records for ‘not smoking\’ at birth, which is likely to be an error so data for this health board has been excluded.xNot available - Between 2021 and 2024, Swansea Bay submitted a very high number of records for ‘not smoking\’ at birth, which is likely to be an error so data for this health board has been excluded.
Cwm Taf Morgannwg3,8643,80554015328.398.5
Aneurin Bevan4,9504,688577569.794.7
Cardiff & Vale4,8714,69741610324.896.4

Metadata

Title

Number and percentage of women who 'stopped smoking' during pregnancy, by health board providing the service

Last update

August 2025 August 2025

Next update

July 2026 (provisional)

Publishing organisation

Welsh Government

Source 1

Maternity Indicators data set

Contact email

stats.healthinfo@gov.wales

Lowest level of geographical disaggregation

Local health boards

Geographical coverage

Local health boards

Languages covered

English and Welsh

Data licensing

You may use and re-use this data free of charge in any format or medium, under the terms of the Open Government License - see http://www.nationalarchives.gov.uk/doc/open-government-licence

Keywords

maternity; stopped smoking; quit smoking

General description

This data is derived from the Maternity Indicators dataset which is provided to the Welsh Government by Digital Health and Care Wales (DHCW).
The Maternity Indicators dataset was established in 2016. It combines records from a mother’s initial assessment with a child’s birth record and enabled Welsh Government to monitor its initial set of outcome indicators and performance measures (Maternity Indicators) which were established to measure the effectiveness and quality of Welsh maternity services.
The Maternity Indicators dataset allows us to analyse characteristics of the mother’s pregnancy and birth process. The process for producing this data extract is complex largely because there can be multiple initial assessment data and records for both initial assessments and births are not always complete.
Full details of every data item available in the Maternity Indicators dataset are available through the NHS Wales Data Dictionary: http://www.datadictionary.wales.nhs.uk/#!WordDocuments/datasetstructure20.htm

Data collection and 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.

Smoking at initial assessment:
While there is a high percentage of valid data for smoking status at initial assessment, statistics on smoking at initial assessment and birth are limited by the way in which the data is collected. If CO monitoring is not available, data reliability is dependent on the mother self-reporting accurate information. CO monitoring was largely suspended during the COVID-19 pandemic, so data between 2020 and 2023 is mainly self-reported.
Prior to 2020, the percentage of women CO monitored at initial assessment ranged between 20% and 30%; however, between 2021 and 2022 it dropped to between 1% and 2%. In 2024 the percentage of women CO monitored at initial assessment rose to 28%, close to pre-pandemic levels. Fewer women were CO monitored at birth. Between 2016 and 2020 the percentage of women CO monitored ranged from 1% to 3%, in 2024 it was 9.8%.
E-Cigarette use should not be recorded in this data item and would not be detected by a CO monitor; however, in practice some mothers may self-report as a smoker if they use e-cigarettes and be incorrectly recorded as a smoker. Likewise, some mothers who do smoke may self-report as a non-smoker and be incorrectly recorded as a non-smoker.
The percentage of pregnant women recorded as being a smoker at initial assessment are based on all records where valid data for this data item are recorded. The number of records with no stated smoking status at initial assessment can be found in Table 4 of the Maternity and birth statistics: quality report tables (https://www.gov.wales/maternity-and-birth-statistics-quality-report).' target='newtab'>https://www.gov.wales/maternity-and-birth-statistics-quality-report).
CO monitoring largely stopped during the COVID-19 pandemic which may affect the comparability for data collected before and after 2020. Of those who were reported as smokers, the percent who were recorded because of CO monitoring in each year was: 25% in 2016, 28% in 2017, 29% in 2018, 31% in 2019, 25% in 2020, 1% in 2021, 3% in 2022, 20% in 2023, 30% in 2024.

Smoking at birth:
Smoking at birth statistics are limited for the same reasons as smoking at initial assessment; however, there has also been an increase in missing and invalid data recorded for smoking at birth in recent years. The number of records with no stated smoking status at birth can be found in Table 4 of the Maternity and birth statistics: quality report tables (https://www.gov.wales/maternity-and-birth-statistics-quality-report).' target='newtab'>https://www.gov.wales/maternity-and-birth-statistics-quality-report).

This analysis is based on women who had valid smoking data at both initial assessment and birth. As smoking status is recorded at two points in time only, the data will not show if mothers were smoking throughout the duration of their pregnancy, or how frequently they smoked. In this analysis, those mothers who were recorded as smoking at initial assessment but not smoking at birth are classed as mothers who ‘stopped smoking’ during pregnancy.
The denominator for the percentage calculation is the total records less records with a ‘not stated’ value at either initial assessment, birth or both.

Frequency of publication

Annual

Data reference periods

2016-2024

Users, uses and context

These statistics will be used in a variety of ways. Some examples of these are:
• advice to Ministers
• to inform debate in the Welsh Parliament and beyond
• to make publicly available data on child health statistics in Wales
• monitoring service delivery
• policy development
• providing advice on birth choices
The main users are:
• Ministers, policy officials and the Members Research Service
• local health boards
• the public
• the research community
• students, academics and universities
• Public Health Wales and other NHS organisations
• voluntary birth organisations.

Rounding applied

No rounding applied

Revisions information

The Maternity Indicators dataset is a live database, meaning health boards can amend data for any period. For this data, DHCW take data extracts from a single point in time, for the latest calendar year. This means that if data extracts are taken for previous time periods, they may differ to the data which is published as it may have been revised by health boards. Welsh Government will not make revisions to historical data unless errors are discovered.

Statistical quality

From 1st April 2019 health service provision for residents of Bridgend local authority moved from Abertawe Bro Morgannwg to Cwm Taf. For more information see the joint statement from Cwm Taf and Abertawe Bro Morgannwg University Health Boards (see weblinks). The health board names have changed with Cwm Taf University Health Board becoming Cwm Taf Morgannwg University Health Board and Abertawe Bro Morgannwg University Health Board becoming Swansea Bay University Health Board.
Data for Abertawe Bro Morgannwg and Cwm Taf are available for previous years in this table by selecting the tick boxes in the Area drop-down box.
More detailed information on the sources of data and analyses in this statistical release are provided in the quality report: https://www.gov.wales/maternity-and-birth-statistics-quality-report

Smoking at initial assessment:
Due to data quality issues with the smoking at birth data, smoking at initial assessment for Swansea Bay and Hywel Dda has been excluded from 2021 to 2023 for compatibility purposes.

Smoking at birth:
Swansea Bay was not included in the Wales totals from 2021 to 2024 and Hywel Dda was not included in the Wales totals from 2021 to 2023. In 2024, data for Wales was from the remaining 6 health boards and from 2021 to 2023 was from the 5 remaining health boards. Swansea Bay was excluded from the smoking at birth data due to data quality concerns and Hywel Dda was excluded as they did not provide any data for smoking at birth between 2021 and 2022 and provided incomplete data in 2023. This resulted in excluding smoking at initial assessment for Swansea Bay and Hywel Dda for these time points for compatibility purposes. In 2021 and 2022 Cwm Taf Morgannwg had an unusually high percentage of missing data.

The number of records with missing data has varied throughout the time series and has increased in recent years. The number of missing records can be found in Table 4 of the Maternity and birth statistics: quality report tables (https://www.gov.wales/maternity-and-birth-statistics-quality-report).