Ystadegau mamolaeth a genedigaethau: adroddiad ansawdd

The intention of the maternity and births statistical release is to provide statistics on mothers and babies, throughout the maternity and birth process. The release supports the Welsh Government’s maternity policy development.

The release has been shortened following a review of our statistical outputs. The changes reflect feedback from a public consultation and aim to focus commentary where it adds most value, while ensuring the underlying data remain accessible.

A number of statistics and analyses are produced on areas including:

• how far into pregnancy a woman receives her initial assessment (or booking appointment)
• how many mothers are smokers
• how many mothers are overweight
• the mode of onset of labour, whether pain relief was administered and the mode of birth including planned and emergency Caesarean sections
• number of live births in Wales
• low birthweight rates

In July 2022, a new annual breastfeeding statistical release was published. All breastfeeding analyses which were previously published in the maternity and births release will now be published in this new release.

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

These statistics are derived from two data sources: the Maternity Indicators dataset (maternity dataset) and the National Community Child Health Database (child health database). Both data sources are provided to the Welsh Government by Digital Health and Care Wales (DHCW). 

The maternity 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 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. 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 maternity dataset.

The child health database 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 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.

As part of the Digital Maternity Cymru program local health boards have begun to move to a new digital maternity system enabling fully digital maternity records. Different health boards have moved to the digital system at different points. In some cases, the move to the new system has temporarily affected data quality. Aneurin Bevan University Health Board were the first to move to the digital system in April 2024, followed by Cardiff and Vale University Health Board in July 2025. The 5 remaining health boards moved between March and April 2026, but implementation schedules have varied between health boards. 

Full details of every data item available on both the maternity dataset and the child health database are available through the NHS Wales Data Dictionary.

Data from the maternity dataset only include 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 child health database 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. It also means that data is available for Welsh resident mothers who gave birth in England.

The child health database records both live and stillbirths, however the majority of analysis in the statistical release refers only to live births.

Analysing data from the child health database provides additional information on new-born children which is not available through the Office for National Statistics’ (ONS) official measure on the number of births. Data from both sources is very closely aligned, but the ONS measures allow for more accurate comparisons between UK countries.

Maternity and birth statistics were first published as a single statistical release in October 2019 with new data referring to calendar year 2018. Previously these statistics were published in two separate statistical releases.

Registered births and infant mortality statistics are routinely produced by the ONS and should be used as the main source for the number of births in Wales.

A number of other statistics are published using data sourced from the child health database:

• annual statistical release and quarterly StatsWales updates on the Healthy Child Wales Programme
• quarterly statistics on breastfeeding (StatsWales)
• annual statistics on immunisations (Public Health Wales)

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.

Birth data from the child health database is also published on Health Maps Wales.

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

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 polices.  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 maternity dataset and child health database.

Strengths: maternity indicators dataset

• 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 2 of the Maternity and birth statistics: quality report tables).

Strengths: National Community Child Health Database

• The dataset has long been established, is processed efficiently by DHCW, and aligns very closely with ONS’ measure on the number of births in Wales.
• Data allows for more detailed analysis of birth in Wales than are provided by the ONS births measures.
• 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 3 of the Maternity and birth statistics: 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 maternity dataset does not record information on births which occur outside of country to Welsh resident mothers, but the child health database does. The number of home births recorded in the maternity dataset is lower than the number recorded in the child health database. The differences in these two recording practices largely explain the differences in the number of births in each dataset. 

Limitations: maternity indicators dataset

The maternity dataset 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 maternity dataset, 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, like BMI and gestational age at initial assessment. These records are retained as we are unable to confidently differentiate between these cases and mothers who genuinely have their first assessment close to birth.
• 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.
• Some health boards record data items inconsistently; for example, some health boards record ‘no previous Caesareans’ as 0 while others record it as 99.
• 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.
• The analysis on smoking during pregnancy is limited because CO (Carbon Monoxide) testing is not available for all assessments across all health boards, so some data is included on the mother self-reporting their smoking status. In addition, CO monitoring will not capture mothers who use e-cigarettes, but some health board may record a mother self-reporting as an e-cigarette user as a smoker, so there may be inconsistencies in the recording of this data item.
• 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.
• The Maternity Care in Wales strategy requires the monitoring of a range of data fields which are not currently included in the maternity dataset.

Limitations: National Community Child Health Database

There are few limitations in using data from the child health database, though some potential limitations include:

• While the number of births closely aligns to the ONS measure, there are sometimes very small differences so the two sources are not always 100% coherent.
• 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.
• 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 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.
• Other statistical releases using data from the database are not currently linked to the maternity and births statistical release, these include statistics on the Healthy Child Wales Programme.

Both the maternity dataset and child health database data items are listed in the NHS Wales Data Dictionary. The data dictionary also defines how ethnic groups are classified, namely: White (any white 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); Black (African, Caribbean, any other black background). 

Mode of onset of delivery is defined as follows: Spontaneous: where labour began spontaneously; Induction: Includes medical induction, surgical induction and cases where a combination of both was used; Caesarean: Any caesarean section carried out before the onset of labour; or a planned elective caesarean section carried out immediately following the onset of labour, when the decision was made before labour.

Gestational age is based on the best estimate available for when pregnancy started, based on either date of last menstrual period or from an ultrasound scan.

The broad data processing steps for the maternity dataset is as follows:

• initial assessment and birth data are recorded by health boards on their own systems
• Digital Health and Care Wales (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 child health database:

• 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 child health database 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 births (i.e. twins or triplets)

The data which Welsh Government receives for both datasets contains individual but anonymised records. This means that no person (mother or baby) are 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 pseudoynmised 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, RStudio and Excel.

Welsh Government statistics are published in line with our statement on confidentiality and data access which is informed by the trustworthiness 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

Gestational age at initial assessment

Some women may have had their first initial assessment before the date that has been recorded in the maternity dataset. This is because the merging methodology for the initial assessment and birth record is based on when these occur in the same health board. 

It is possible that a mother could have an initial assessment in one health board, early in the pregnancy, but then if she gives birth in another health board for any reason (for example, unexpected complications, or present in a different health board area at the time) she will have another initial assessment recorded at the second health board where she gives birth. This may explain the small peak around 39 and 40 weeks.

A small proportion of initial assessments (1%) were recorded between 39 and 42 weeks, possibly accounting for mothers who had their initial assessment in one health board, early in the pregnancy, but gave birth in another health board resulting in another initial assessment being recorded at the time of birth. 

The percentage of women who received their initial assessment by 10 completed weeks of pregnancy is based on all records minus records with a ‘not stated’ value for gestational age at initial assessment. ‘Not stated’ also includes records where the gestations was stated as 0 weeks. The number records removed from the calculation can be found in Table 4 of the Maternity and birth statistics: quality report tables.

Mental health conditions reported at initial assessment

The mental health conditions listed on the record are categorised as: puerperal psychosis (severe postnatal depression); bi-polar effective disorder/manic depression; psychosis; psychotic depression; schizophrenia; and other (any other mental health condition).

The Wales-level percentage for pregnant women reporting a mental health condition at initial assessment excludes data from Betsi Cadwaladr because of their low reliability for all years. While at least 99% of records had valid data entered, the large majority were recorded as having no mental health condition which is unlikely to reflect the actual position in this health board. In previous publications data from Cwm Taf/Cwm Taf Morgannwg had also been excluded for the same reason, however the data for this health board has since been ratified and can now be included.

All other health boards have valid data for the mental health data item in at least 88% of records in each year, apart from Cardiff and Vale in 2016 (56% completeness). In 2024 and 2025, Aneurin Bevan have been excluded from the mental health at initial assessment analysis due to high levels of missing data (76% and 100%). For 2016 to 2023, the Wales total represents data from 6 health boards. 

The percentages for the number of pregnant women reporting a mental health condition at initial assessment are based on all records minus records with a ‘not stated’ value for mental health condition. The number of records removed from the calculation can be found in Table 4 of the Maternity and birth statistics: quality report tables.

BMI at initial assessment

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 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 9% to 15% of all pregnancies have been excluded for this reason in each year.

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/Cwm Taf Morgannwg in 2016 (77%), 2019 (88%) and in 2024 (88%); Betsi Cadwaladr in 2019 (89%) and Aneurin Bevan in 2024 (23%).

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.

Weight gained during pregnancy

To calculate the amount of weighed gained, each mother needs a valid weight recorded at initial assessment and between 36 to 38 week or at birth. There is a relatively high proportion of missing data for mothers’ weight at birth which limits the reliability of the weight gain data. 

From 2020 to 2023, Hywel Dda health board have provided little or no data for mother’s weight at birth. Swansea Bay provided little or no data from 2021 and 2025. As a result, the Wales data excludes these health boards. In 2024 Aneurin Bevan has been excluded as it has high levels of invalid data for weight at birth. The percentage of records with valid data for this calculation for each year are: 2025 ( 76%); 2024 (83%), 2023 (63%); 2022 (64%); 2021 (61%); 2020 (73%); 2019 (80%); 2018 (75%); 2017 (70%); 2016 (55%). As a result of the level of missing data, caution is advised when using this statistic. 

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 has largely been suspended since the COVID-19 pandemic began, 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 2025 the percentage of women CO monitored at initial assessment was 26%, 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 2025 it was 9%.

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, and for Swansea Bay in 2024, for compatibility purposes.

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.

Similarly, the analysis by age requires valid data for smoking status at initial assessment as well as age. The number of records with either of these data items missing can be found in Table 4 of the Maternity and birth statistics: quality report tables.

Further, the analysis by ethnic group requires valid data for smoking status at initial assessment as well as ethnic group. The number of records with either of these data items missing can be found in Table 4 of the Maternity and birth statistics: quality report tables. 

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, 28% in 2025. 

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.

Similarly, the analysis by age requires valid data for smoking status at birth as well as age. The number of records with either of these data items can be found in Table 4 of the Maternity and birth statistics: quality report tables.

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. From 2020 to 2022 Cwm Taf Morgannwg had an unusually high percentage of missing data.

Stopped smoking during pregnancy

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. For the purpose of this release 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. 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.

Onset of labour

Data was recorded in the maternity dataset for every health board; however, in Hywel Dda health board (between 2016 and 2021) and Aneurin Bevan health board (between 2016 and 2023), labour onset has not been recorded as ‘caesarean’ when an elective caesarean section birth occurred in these years of data. Aneurin Bevan did record data in 2024 however it was incorrectly coded. As a result of this data quality issue, these health boards have been excluded from the analysis for each year. For 2024, the statistics presented at Wales-level are based on the 20,049 deliveries which took place at the remaining 6 health boards.

The number of records which had missing data for the onset of labour can be found in Table 4 of the Maternity and birth statistics: quality report tables.

Pain relief

The percentage of records with valid data for epidurals is mixed across health boards and years, and in 2025, 96% of records had valid data at all Wales level. 6 out of 7 health boards had valid data for 99.9% or more of their records. Cardiff and Vale health board had the lowest percentage of valid data (81%).

At the Wales level, the number of records with missing data for pain relief can be found in Table 4 of the Maternity and birth statistics: quality report tables.

Mode of birth

The percentages are based on records with valid data recorded for mode of birth. In 2024, Aneurin Bevan did not provide correctly recorded data for this data item so have been excluded from the analysis, and the Wales totals are based on the remaining 6 health boards.

Births in Swansea Bay health board 2025

From 2 September 2024 the maternity and neonatal units at Princess of Wales Hospital in Bridgend were temporarily closed for major refurbishments.  Patients were directed to alternative units in nearby hospitals. All services were resumed by 20 February 2025.

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 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 support the Welsh Government maternity vision: Maternity Care in Wales, A Five Year Vision for the Future (2019-2024).

Statistics also support analysis of key public health topics like breastfeeding and smoking and obesity in pregnancy.

Background information about statistics and sources is published for users and 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 maternity dataset was recently established 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.

There are however specific issues with a few of the data items where the data provided does not wholly align with the Data Dictionary specification and where some health boards have difficulties providing the required data. Only a selection of the available data items has been included in this statistical release but as the data quality improves we hope to expand its scope and depth.

A comparison of the total number of records per year is shown in Table 1 of the Maternity and birth statistics: quality report tables.

Table 2,  Table 3 and Table 4 of the maternity and birth 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 maternity dataset but only in 2021 onwards in the child health database. 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 maternity dataset only includes data on mothers and babies where the initial assessment and birth occurred in the same health board. 

Data from the child health database 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 4 of the maternity and birth statistics: quality report (tables).

Both the maternity dataset and child health database 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 maternity dataset 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 maternity dataset extracts to be produced by DHCW for the full time series, therefore data and trends published in previous publications may have changed.

The percentages in this release are rounded. Percentage point changes are calculated based on the unrounded numbers.

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 2024 for the reference year 2023. 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.

Coherence and comparability

Data from the maternity dataset 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.

Maternity and birth statistics for other UK countries is available.

Scotland: Births in Scottish Hospitals

Northern Ireland: Birth Statistics

England: NHS Maternity Statistics

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.

All our webpage headlines are published in Welsh and English.

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 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 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 child health database and the maternity dataset. The child health database 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 maternity dataset combines a child’s birth record with their mother’s initial assessment record (where possible). 

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. 

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 provision of maternity services and information about number of births and their characteristics 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.

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

Rydym yn croesawu adborth ar unrhyw ystadegau bob amser. Os hoffech wneud sylwadau, anfonwch e-bost at ystadegau.iechyd@llyw.cymru.