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Publication, Part of

NHS Maternity Statistics, England - 2020-21

Official statistics

Current Chapter

Comparison of Data Common to HES and MSDS


Comparison of Data Common to HES and MSDS

This is the fifth annual report on NHS Maternity Activity which brings together established HES data with data from the MSDS which is a maturing, national-level dataset which has been impacted in terms of non-response from providers as they work towards establishing their reporting flows. 

In April 2021 the MSDS transitioned to a new version of the dataset. MSDS v2.0 was an update to the previous data set that introduced a new structure and content, including clinical terminology, in order to meet current clinical practice and incorporate new requirements. This is the second publication of data from MSDS v2.0, therefore data from this year and 2019-20 are not directly comparable to earlier years. More information about the changes for MSDS v2.0 can be found here.

This section reports on the similarities and differences in terms of coverage and nature of reported activity between both data sets.

Both the HES and MSDS record some core data about each delivery and pregnancy including method of delivery, onset of labour, gestation at delivery and gestation at the first antenatal assessment / booking appointment.


Comparison of deliveries

The MSDS is a maturing data set and reporting coverage continues to improve. However it does not yet capture as many deliveries as are recorded in HES.

The proportion of deliveries in the MSDS compared to HES was 86.2 per cent in 2020-21.

In 2019-20, the MSDS transitioned to a new version of the dataset, meaning the data from the current year and 2019-20 are not directly comparable to earlier years.


Deliveries by method of onset

The proportion of deliveries with each of onset of labour method is different between HES and MSDS, but this difference is only larger than 3 percentage points for the Unknown and Missing entries.



Last edited: 9 March 2022 11:27 pm