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Maternity Services Monthly Statistics June 2019, experimental statistics

Official statistics, Experimental statistics

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Differences between the new and previous versions of the data set

Differences between the new and previous versions of the data set


Maternity Services Data Set (MSDS) v2.0 is an update to the existing data set that introduces a new structure and content, including clinical terminology, in order to meet current clinical practice and incorporate new requirements. MSDS v2.0 also mandates the submission of all maternity records in scope of the data set, including records that are held on paper which must be submitted in the required electronic format.

MSDS v2.0 is designed to meet requirements that resulted from the National Maternity Review, which led to the publication of the Better Births report in February 2016. Better Births highlighted the need for maternity services in England to become safer, more personalised and provide better access to information for pregnant women. The publication of Better Births resulted in the establishment of the Maternity Transformation Programme, and the updated version of the data set forms part of the ‘Sharing Data and Information’ workstream of the programme.

The previous version of the dataset, MSDSv1.5 ceased collection with March 2019 data that was published in June 2019.

Clinical terminology

The MSDS now allows clinical coding to be submitted and a number of data items previously submitted as values in specific fields have been removed from the dataset and are now expected to be submitted using clinical coding. This includes the following.

  • Measurements, such as women’s height, weight, BMI and babies’ birthweight and Apgar score.
  • Diagnoses and conditions including those that may have an impact on pregnancy, such as diabetes.
  • Procedures and other clinical interventions such as episiotomy, anaesthesia and screening tests.
  • The preferred terminology is Snomed CT, however until Snomed is mandated in 2020, submitters are able to send data in other terminologies, such as Read, ICD10 and OPCS. Where possible, terminologies will be mapped.

The introduction of clinical terminology allows the dataset to be more flexible and will allow the collection of new data items in the future via the submission of new codes, rather than requiring a change to the structure of the dataset.

Data collection

From April 2019 data, the MSDS is collected via the Strategic Data Collection Service (SDCS) Cloud. Prior to this, MSDS data was collected via the Bureau Service Portal.

Unlike the Bureau Service Portal, the SDCS Cloud is an internet-facing service that does not require an N3 or HSCN connection, making it easier for providers to submit data and therefore enabling better coverage in published statistics. This new service stores MSDS data in cloud-based infrastructure.

Detailed guidance is available to support providers in making submissions via the SDCS Cloud. This includes detailed technical and user guidance. New providers must complete a defined process to gain access to the SDCS Cloud. It also uses two-factor authentication as the secure method of confirming user identity using a combination of two different factors.

Data validation

The data is validated at the point of submission, for each provider. If file-level validation checks are not passed the provider will receive a file-level rejection report. If file-level validation is passed, the data are successfully submitted but the provider will still receive a report containing details of field-level errors and warnings. These can be investigated, corrected and further submissions can be made within the submission window.

Data processing

From April 2019 data, the MSDS data are processed using NHS Digital’s new Data Processing Services (DPS). DPS use modern technologies and processes to collect, process and access data more efficiently.


During processing a number of derivations are applied to the submitted data in order to make it more useful for internal analysis, publication and to external customers. These derivations include:

  • System data such as submission dates and row counts.
  • Geographical data such as local authority, electoral ward, CCG of residence.
  • Demographics based on identifiable data such as age at booking, deprivation.
  • Items based on clinical coding like smoking status, BMI, birth weight and Apgar Score.

A full list of data items, including derivations, is available from the Technical Output Specification (TOS)

Data security and patient identifiers

Patient Identifiers

Mothers and babies are uniquely and safely identified in MSDSv1.5 using the pseudonymised data items, MSDS_ID_Mother and  MSDS_ID_Baby. These items are derived from a combination of identifiable data items, such NHS number, date of birth, postcode and gender to search a patient index and apply an existing ID to matching patients already present in the index or allocate a new ID for new patients. The index is common to both MSDS and the Community Services Dataset (CSDS), allowing linkage to track patients accessing both services.

MSDSv2.0 uses the new Master Person Service (MPS), to allocate similar pseudonymised items, PERSON_ID_Mother and  PERSON_ID_Baby. The MPS is an enhanced patient-matching algorithm that increases the number of linkable records where incomplete records have been submitted. It is intended that MPS is commonly used across a large number of datasets, facilitating simpler data linkage.

The two methodologies are not compatible, however the new PERSON_IDs created by the MPS will be retrospectively applied to MSDSv1.5 data, making it possible to track mothers who have babies over the lifespan of both datasets.

Unique Pregnancy ID

Unique Pregnancy ID is used to identify events such as antenatal bookings, screening tests, births and clinical interventions across a single pregnancy. In MSDSv1.5, this field (called UniquePregID) is derived using a combination of MSDS_ID_Mother and Estimated Date of Delivery.

In MSDSv2.0, the equivalent field (called UniqPregID) is created differently. In the new dataset, providers are able to submit their own values (in the field PregnancyID) and these are also used in the derivation.

In common with patient identifiers, these are not compatible across the two datasets, but the new version of the field will again be retrospectively applied to the previous dataset enabling events to be linked for pregnancies that begin in MSDSv1.5 and conclude in MSDSv2.0


These statistics are disseminated via the NHS Digital website.

The format of the monthly maternity publication based on MSDSv2.0 has changed from earlier publications in that we have moved to an HTML based publication format following Government Digital Service/UK Statistics Authority recommendations about making our data more accessible and user friendly to readers.

The new format is less reliant on downloading and opening attachments, allowing the data to accessed directly on screen. This will allow for more interactive content to be displayed.

The data used in this publication is available in a CSV to comply with Open Government Licence standard on Open Data.

Access to data

In addition to the open data file available as part of the monthly publication, bespoke extracts of MSDS data are available on request from the Data Access Request Service (DARS).

Review and feedback

The statistics presented in this publication are currently designated as experimental statistics and, as such, remain under constant review.

The Maternity Analysis team welcomes any comments or feedback on the publication.

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Last edited: 1 October 2021 9:40 am