Breastfeeding data: quality report

The breastfeeding statistical release provides statistics on mothers and babies, immediately following the birth and through the first 6 months after the birth.

Statistics and analyses cover areas including:

• breastfeeding by age of child
• breastfeeding by age of mother
• breastfeeding by ethnic group
• breastfeeding by place of birth

From July 2022, a new annual breastfeeding statistical release was published for the first time. Prior to this, all breastfeeding statistics were previously published in the maternity and births release.

The breastfeeding statistical release provides data to support the All Wales breastfeeding 5 year action plan as well as the Wellbeing of Future Generations act 2015 which states that every child in Wales should receive the best start in life.

The release also supports the Welsh Government maternity vision: Maternity Care in Wales, A Five Year Vision for the Future (2019-2024), published in July 2019.

These statistics are derived from two data sources: the Maternity Indicators dataset (MI ds) for mothers’ intention to breastfeed and the National Community Child Health Database (NCCHD) for breastfeeding at all other ages. Both data sources are provided to the Welsh Government by Digital Health and Care Wales (DHCW).

The MI ds 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 MI ds allows us to analyse characteristics of the mother’s pregnancy and birth process, of which ‘intention to breastfeed’ is one. 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. In merging initial assessment data with birth record data, DHCW take the following validation steps:

• initial assessment and birth records where the mother’s NHS number is missing are removed
• birth records where the baby has no NHS number are removed, all other birth records are retained
• data from the initial assessment is merged with the birth record using the mother’s NHS number, which should be a unique identifier on both records
• records where the health board providing the initial assessment and where the birth occurred are the same, are retained, all other initial assessment data are removed
• where the birth record could not be matched to an initial assessment record, the birth record is still retained, and all initial assessment data will be missing
• records where the number of days between the initial assessment and date of birth is between -1 and 315 are retained
• where there are still multiple initial assessment records for a birth, checks are performed to establish the most complete merged record; that record is then retained, and any remaining duplicates are removed

This complex process results in many records being removed from the dataset, therefore there are limitations in the use of statistics produced from the MI ds.

The NCCHD was established in 2004 and consists of anonymised records for all children born, resident or treated in Wales and born after 1987. The database brings together data from local Community Child Health System databases which are held by local health boards (LHBs) and its main function is to provide an online record of a child’s health and care from birth to leaving school age. The statistics used in this release are based on the data recorded at birth and shortly after birth.

Local Community Child Health Systems change over time to meet changing requirements; the latest and fourth version is known as the Children and Young Persons Integrated System (CYPrIS) and was rolled out to all health boards during 2019. More information on its features is available on the DHCW website.

Full details of every data item available on both the MI ds and NCCHD are available through the NHS Wales Data Dictionary.

Data from the MI ds 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. It does not include any births for Welsh resident mothers who gave birth in England or in any other country outside of Wales.

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 NCCHD includes records of all children born in, resident in or receiving services in their relevant local health boards. This means the database contains some information for some children not currently residing in Wales; however, unless otherwise stated, all statistics produced from data sourced from this database is filtered to only include those children born in Wales.

Data on breastfeeding at birth, 10 days, 6 weeks and 6 months refers to the time period in which the activity occurred, rather than when the child was born.

The NCCHD records both live and stillbirths, however the analysis in the statistical release refers only to live births.

As well as the annual statistics, quarterly statistics on breastfeeding are also published in February, May, August and November of each year, using data sourced from the NCCHD.

The National Maternity and Perinatal Audit (NMPA) publish reports on topics such as neonatal mortality and breastfeeding in neonatal units which includes data for Wales.

Breastfeeding at birth data from NCCHD is also published on Health Maps Wales.

These statistics are 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 infant feeding 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
• breastfeeding support organisations

If you are a user and do not feel the above list adequately covers you, or if you would like to be added to our circulation list, please let us know by e-mailing stats.healthinfo@gov.wales.

Strengths: in general for both data sources

• Data collected is used operationally by health boards so there is no additional burden on data suppliers and there are not any survey sampling issues.
• There are a wide range of data items available, allowing for a broad overview of maternity and birth statistics for mothers receiving services in Wales.
• Data is collected on a broadly consistent basis across Wales, though there are some differences in health board systems and methods of recording data.
• The main statistics from both sources largely meet the needs of users and support Welsh Government in making evidence based policies. The majority of data is available through these sources to monitor key performance indicators which the Welsh Government sets for local health boards.
• Statistics are published regularly and as timely as possible, with additional tables published on StatsWales.
• The number of births recorded in hospitals is very closely aligned between both the MI ds and NCCHD.

Strengths: MI ds

• The merging of the initial assessment and birth records allow us to analyse data across the whole maternity and birth process. It allows for monitoring areas of interest such as smoking during pregnancy and bespoke analysis can be performed such as analysing birth outcomes when the mother is overweight.
• The data is an administrative source which has a reasonable level of completeness across most data items, across all health boards (completeness tables shown in Table 1 and Table 2 of the Breastfeeding: quality report tables).

Strengths: NCCHD

• The dataset is long established and processed efficiently by DHCW.
• Data allows for more detailed analysis of births and breastfeeding in Wales which is not possible with other official sources of births data such as those published by the ONS: Births in England and Wales: 2024.
• The data is an administrative source which has a high level of completeness across most data items, across all health boards (completeness tables shown in Table 1 and Table 2 of the Breastfeeding: quality report tables).

Limitations: in general for both data sources

• The StatsWales information is intended for a more informed audience, without full explanatory notes.
• As data is typically inputted into the computer system manually in the health boards, there is a risk of human processing errors.
• The MI ds does not record information on births which occur outside of country to Welsh resident mothers, but the NCCHD does. The number of home births recorded in the MI ds is lower than the number recorded in the NCCHD. The differences in these two recording practices largely explain the differences in the number of births in each dataset.

Limitations: MI ds

The MI ds is a complex dataset, which is subject to extensive validation processes. There are a number of limitations in the statistics produced from this data source. Some of the limitations include:

• Initial assessment data is only included for records where the initial assessment and birth took place in the same health board. This creates two significant limitations:
  • Initial assessment records where the initial assessment takes place in a different health board to the birth are removed in the merging process and are not accounted for in any of the analysis.
  • If a mother has an initial assessment in one health board and gives birth in a different health board but her information from the initial assessment is not transferred, a second ‘initial assessment’ may occur in the health board where the birth occurs. This means that this record will be included in the MIDs, but the information for the initial assessment will come from the second assessment and is likely to be significantly different for a number of data items.
• While data completeness is relatively good for most data items, it can be mixed for some data items, particularly when assessing coverage at health board level. This means changes over time should always be assessed with their data completeness in all years, as any perceived changes may be due to changes in data coverage rather than actual changes in the trend.
• Data validation rules for health boards are not entirely consistent; some data items contain values which are not valid according to the data dictionary.
• Values for some raw data items are obviously incorrect; for example, thousands of records have unrealistic values for mother’s heights and weights which need to be removed from the published statistics. This raises questions around the general reliability of data recording across all data items.
• Births outside of hospitals (usually at home) are sometimes, but not always recorded in the database, and the way the data is recorded does not always allow us to identify in which setting the birth occurred.

Limitations: NCCHD

There are few limitations in using data from the NCCHD, though some potential limitations include:

• While data completeness for most data items is very high, they might not always be 100% complete so there may be a small amount of missing data.
• The completeness of the breastfeeding decreases considerably over time from birth (7.7% missing records in 2024) to 10 days (12.1% missing records in 2024), to 6 weeks (21.0% missing records in 2024) with 6 months (21.8% missing records in 2024) having the lowest level of completeness.
• Data on ethnic group is much less complete than most other data items in the database.
• Data from the database is not currently linked to the Maternity Indicators dataset; if it was then there would be potential to extend analysis to assess the relationship between events which happen in pregnancy with outcomes for the child after birth and in their early years. For example, analysis could be produced on the relationship between the timing of the initial assessment and breastfeeding rates.

Both MI ds and NCCHD data items are listed in the NHS Wales Data Dictionary.

The data dictionary defines how breastfeeding status is classified, namely:

• exclusive breastfeeding (breastfeeding or receiving breast milk by any other means e.g. tube, cup, syringe etc and essential medication)
• combined milk feeding – predominantly breast (more than 75% of the feeds in the previous 24 hours were breastfeeds)
• combined milk feeding – partially breast (75% or less of the feeds in previous 24 hours were breastfeeds)
• artificial milk feeding (formula milk and any other drink but no breast milk)

It is intended that milk feeding should be recorded as exclusive breast milk feeding even if solid food has been introduced if breast milk is the only source of fluids. As other drinks are introduced milk feeding should be recorded as combined milk feeding (predominant or partial as appropriate).

The data dictionary also defines how ethnic groups are classified, namely:

• White (any white background)
• Black (African, Caribbean, any other black background)
• Asian (Pakistani, Bangladeshi, Chinese, Indian, any other Asian background)
• Mixed/multiple (white and Asian, white and black African, white and black Caribbean, any other mixed background)
• Other (any other ethnic group)

The broad data processing steps for the MI ds is as follows:

• initial assessment and birth data are recorded by health boards on their own systems
• DHCW extract data from health boards, once a month
• DHCW inform health boards that data extracted in April, will be used in Official Statistics for the previous calendar year, allowing health boards time to ensure their data is as complete as possible by this date
• DHCW stores the data on temporary databases before merging the two datasets
• records are merged by using a combination of the mother’s NHS Number and the date of initial assessment from both temporary datasets
• DHCW perform additional validation on the data and then send to the Welsh Government a pseudonymised data extract in May

A similar data processing cycle exists for the NCCHD:

• health boards enter data onto their own child health systems
• DHCW extract data every quarter and store in their own database
• a grouping process is then applied to the database using valid anonymised NHS numbers so that records relating to the same child can be identified
• the NCCHD is built from this data with the aim of obtaining maximum record completeness
• the extract taken in April is used for births occurring in the previous calendar year and a pseudonymised version is sent to Welsh Government for use in this statistical release

Once data is received by Welsh Government, a range of data validation checks are performed, these include:

• identifying duplicate records
• deriving the number of babies born from each pregnancy
• identifying incorrect data for mother heights and weights and recalculating BMI
• recoding invalid data values to the value for ‘not stated’
• recoding blank fields to the value for ‘not stated’
• standard sense checks against previous years’ data
• checking that data items for certain fields are consistent between records where there was a multiple birth (i.e. twins or triplets)

The data Welsh Government receives for both datasets contains individual but anonymised records. This means that no person (mother or baby) is identifiable in either dataset.

DHCW take several steps to protect personal information before sharing it, and Welsh Government take disclosure control steps before publishing data, these include:

• creating pseudonymised ID’s for mothers and babies which are unique identifiers, based on NHS numbers, which cannot be traced back to the actual NHS number by anyone who sees the Welsh Government data extract
• names and dates of birth are not included in either dataset
• Welsh Government publishes statistics at aggregated levels
• any counts under 3 for any specific data item are supressed before publication

Data is submitted on Excel spreadsheets via DHCW’s secure web data transfer system or secure email. Data is stored and analysed using SQL databases, Microsoft Access, R and Excel.

Welsh Government statistics are published in line with our statement on confidentiality and data access which is informed by the trustworthiness (UK Statistics Authority) pillar contained in the Code of Practice for Statistics. A statement of how we conform to the pillars of Trustworthiness, Quality and Value is published in our annual statistical bulletin.

Data quality of specific data items

Broad data quality

Statistics published by Welsh Government adhere to the Statistical Quality Management Strategy which supplements the Quality pillar of the Code of Practice for Statistics (UK Statistics Authority) and the European Statistical System principles of quality for statistical outputs. This statistical release aims to meet these quality principles in the following ways.

Relevance 

The statistics provide an overview of maternity services and birth characteristics in Wales. The statistics provide data to support the All Wales breastfeeding 5 year action plan, the Welsh Government maternity vision: Maternity Care in Wales, A Five Year Vision for the Future (2019 to 2024), as well as the Wellbeing of Future Generations act 2015 which states that every child in Wales should receive the best start in life.

The statistics also support analysis of key public health topics like breastfeeding rates.

Background information about statistics and sources is published for users and we encourage users of the statistics to contact us to let us know how they use the data.

We consult with key users prior to making changes, and where possible publicise changes on the internet, at committees and other networks to consult with users more widely. We aim to respond quickly to policy changes to ensure our statistics remain relevant.

Accuracy and reliability

The MIDs was established in 2016 and data quality is mixed. Welsh Government and DHCW are working with health boards to improve completeness and quality. In comparison with other sources of births and maternity data, overall counts and key statistics align reasonably well, given the limitations created by the complex merging process.

Table 1 and Table 2 of the Breastfeeding statistics: quality report (tables), show how complete individual data items are across both sources. If a data item has a value entered which is equivalent to ‘not stated’ this is considered incomplete data in all years of the MI ds but only in 2021 onwards in the NCCHD. In years prior to this, a ‘not stated’ value was considered valid. Missing or blank data is considered incomplete for all years in both datasets.

Note that data from the MI ds only includes data on mothers and babies where the initial assessment and birth occurred in the same health board.

Data from the NCCHD includes data on children born to Welsh residents and on children born in Welsh hospitals to non-Welsh residents. Statistics in this release are generally filtered on those children born in Wales to Welsh residents.

The charts and tables in the statistics may include categories for not stated data. Calculated percentages exclude not stated values from the denominator unless otherwise stated.  The quantity of missing data for each data item is referred to throughout the text and in Table 1 and Table 2 of the Breastfeeding statistics: quality report (tables).

Both MI ds and NCCHD are live databases, meaning health boards can amend data for any period. For the statistics in this release, 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. In the case of incorrect data being published, revisions would be made and users informed in conjunction with the Welsh Government’s revisions, errors and postponements policy.

Note that in 2019, new data from the MI ds was published for calendar years 2016, 2017 and 2018. Previous maternity statistics publications were experimental statistics, based on financial years. Publishing on a calendar year basis required new MI ds extracts to be produced by DHCW for the full time series, therefore data and trends published in previous publications may have changed.

Timeliness and punctuality 

Data is published as soon as is practicable.

The data provider (DHCW) extracted both datasets in the April following the reference year, for example data was extracted in April 2025 for the reference year 2024. This allows some tolerance for health board’s late recording of maternity and birth information. Health boards are informed when data will be extracted and they endeavour to keep information accurate at this point in time.

Publication dates are announced well in advance and any delays are communicated via notices on our website. Any revisions or postponements to outputs follow the revisions, errors and postponements policies published online.

Coherence and comparability 

Data from the MI ds 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.

Information is provided on why the number of births between sources is different. Comparisons of births between different parts of the UK should be made using ONS data which is collected on a comparable basis.

Breastfeeding statistics for other UK countries

Scotland

Infant feeding statistics (Public Health Scotland)

Northern Ireland 

Breastfeeding | Department of Health

England

Breastfeeding statistics (Office for Health Improvement and Disparities)

Accessibility

The statistics are published in an accessible, orderly, pre-announced manner on the Welsh Government website at 9:30am on the day of publication. An RSS feed alerts registered users to this publication. Simultaneously the releases are also published on the National Statistics Publication Hub. 

Statistical releases are publicised on X and all releases are available to download for free. 

Descriptions are provided for all charts and tables so that they can be read with a screen-reader.

Data is published on StatsWales which allows users to download and link data in an open data format. 

Plain English is used in our outputs as much as possible and all outputs adhere to the Welsh Government’s accessibility policy.

Official statistics status

All official statistics should show the standards of the Code of Practice for Statistics (UK Statistics Authority).

These are accredited official statistics. They were independently reviewed by the Office for Statistics Regulation as part of two assessments covering Statistics on births, infant mortality and teenage conceptions in 2011 (OSR) and Statistics on health and personal social services in Wales (OSR) in 2012. They comply with the standards of trustworthiness, quality and value in the Code of Practice for Statistics.

It is Welsh Government’s responsibility to maintain compliance with the standards expected of accreditation. If we become concerned about whether these statistics are still meeting the appropriate standards, we will discuss any concerns with OSR promptly. Accreditation can be cancelled or suspended at any point when the highest standards are not maintained, and reinstated when standards are restored.

Accredited official statistics are called National Statistics in the Statistics and Registration Service Act 2007.

Statement of compliance with the Code of Practice for Statistics

Our statistical practice is regulated by the Office for Statistics Regulation (OSR). OSR sets the standards of trustworthiness, quality and value in the Code of Practice for Statistics that all producers of official statistics should adhere to.

All of our statistics are produced and published in accordance with a number of statements and protocols to enhance trustworthiness, quality and value. These are set out in the Welsh Government’s Statement of Compliance.

Since the statistics were originally assessed, the data sources from which the statistics are generated has changed, and the maternity and births release covers a much wider range of factors than at the time of the initial assessment. Breastfeeding statistics are also now reported separately.

Given the change of data sources, OSR agreed to carry out a compliance review of both sets of statistics to determine whether the accredited official statistics status is still appropriate for the releases

OSR found the Maternity and births statistics and Breastfeeding statistics to continue to comply with the Code of Practice for Statistics (UK Statistics Authority) and should continue to be designated as accredited official statistics.

These accredited official statistics (OSR) demonstrate the standards expected around trustworthiness, quality and public value in the following ways.

Trustworthiness

The data used in this statistical release is collected via two sources, the NCCHD and the MI ds. The NCCHD consists of anonymised records for all children born, resident or treated in Wales and born after 1987. It brings together data from the child health system databases which are held by local health boards. This is a long-established data collection and database. The MI ds combines a child’s birth record with their mother’s initial assessment record (where possible). There are some data quality issues with certain data items in this dataset which are explained in more detail in the quality report.

Quality

The published figures provided are compiled by professional analysts using the latest available data and applying methods using their professional judgement and analytical skillset. Statistics published by Welsh Government adhere to the Statistical Quality Management Strategy which supplements the Quality pillar of the Code of Practice for Statistics and the European Statistical System principles of quality for statistical outputs.

The NCCHD data included in this release comes from administrative data collection forms which are used in the management of the Healthy Child Wales Programme. The data is dependent on local authorities maintaining accurate records but systems are well established and reliable.

Data is collected by Digital Health Care Wales directly from local health boards via local Child Health Systems.

Validation checks are performed by Welsh Government statisticians and queries referred to local health boards where necessary. The statistical release is then drafted, signed off by senior statisticians and is published in line with statement on confidentiality and data access which is informed by the trustworthiness pillar contained in the Code of Practice for Statistics.

Value

The purpose of the statistical release is to provide evidence for policy development; to allow local health boards to monitor and benchmark their service provision against all other local health boards in Wales; and to inform for the wider public about breastfeeding rates in Wales. This annual statistical release also supports the Welsh Government’s long-term plan for health and social care: A Healthier Wales.

You are welcome to contact us directly with any comments about how we meet these standards. Alternatively, you can contact OSR by emailing regulation@statistics.gov.uk or via the OSR website.

Dissemination 

Given the strengths and limitations listed above, data from both the MI ds and NCCHD are of sufficient quality to justify publication. An extensive statistical release is published with high level summaries and charts, with interactive data tables are published on StatsWales.

Evaluation

We always welcome feedback on any of our statistics. If you would like to make any comments, please e-mail us at stats.healthinfo@gov.wales