July 5, 2021

University of Nottingham research could finally demonstrate the need for routine GBS testing in the NHS

In the summer of 2020 the University of Nottingham received approval to commence in leading a large study into the routine testing of GBS infection in pregnancy: “THE CLINICAL AND COST-EFFECTIVENESS OF TESTING FOR GROUP B STREPTOCOCCUS IN PREGNANCY: A CLUSTER RANDOMISED TRIAL WITH ECONOMIC AND ACCEPTABILITY EVALUATIONS (GBS3)”. The trial has now completed its initial phase of recruiting a number of different English hospital Trusts into the study.

So, what will this study investigate?

This is a large and complex trial, involving up to 320,000 women, which will take some time to complete, up to 42 months or longer. The primary objectives of the trial will be to review three main groups of women, whose hospitals will be randomly allocated to offer three different types of treatment:

  • a GBS rapid test offered with consent as part of standard care;
  • a “gold standard” EMS test offered with consent as part of standard care;
  • the current UK standard treatment, so they only tested if they are deemed “high risk” for GBS carriage.

As these tests will become the standard practice offered to all women at the units participating in the research, they will not need to be consented into the study. The data collected from the research will be accessed as part of standard access to NHS anonymised data for qualitative data collection on maternal GBS and neonatal GBS infection rates.

Later on in the study a much smaller group of women will be invited to take part in quantitative research, to answer questions about their experience with GBS testing.

What will the study seek to establish?

The study’s main aim is to question whether routine testing of women for GBS colonisation, either in late pregnancy or during labour, reduces the occurrence of early-onset neonatal sepsis, when compared to the current risk-factor-based strategy.

The trial will also address secondary questions of effectiveness of the testing, acceptability, implementation, and cost-effectiveness.

When reviewing effectiveness, the trial will assess whether secondary outcomes are impacted, whether a higher rate of women with known colonisation four hours prior to delivery are identified, whether coverage is affected by the type of testing offered, and finally – and perhaps most importantly – whether routine testing reduces neonatal unit admissions when compared to the current strategy and which testing approach works best to do this.

Whether the testing is acceptable or not will also be established by the study. For example, the study will assess whether there are any barriers to implementing a particular routine testing strategy, or whether context and process mechanisms influence how it is acceptably implemented such as place of birth, age, socioeconomic group, or ethnicity.

The implementation of the testing itself will also be evaluated. This will include looking at the key process parameters that can predict reduced neonatal admission, whether unit level factors influence uptake, and how processes can be influenced to maximise the impact of routine testing.


This is a very exciting study and it will be interesting to see whether the independently reviewed data will support the need to invest NHS funds in the routine screening of pregnant women for GBS colonisation. Many other countries adopt a routine screening approach and the UK lags behind this adopted cautious approach.

Hopefully GBS awareness month will raise awareness of the risks of unknowingly carrying GBS infection in late pregnancy, as well as help people to understand their options for procuring further advice, guidance and where to seek private ECM gold standard tests.

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