Landmark group B Strep testing trial in pregnant women begins

Thursday, 21 October 2021
A major clinical trial has started which aims to improve the prevention of potentially life-threatening infection caused by group B Streptococcus in newborn babies in the UK.

Group B Strep (GBS) is the most common cause of life-threatening infection in newborn babies, causing pneumonia, meningitis and sepsis.

The new trial, led by experts at the University of Nottingham, is the first in the world to measure the effectiveness of two tests to identify group B Strep bacteria in late pregnancy or labour, compared with the current approach of identifying pregnant women with ‘risk factors’ for their newborn developing the infection.

The GBS3 trial, which is funded by the NIHR Health Technology Assessment (HTA) Programme, will involve 80 hospitals in England, Wales and Scotland and will assess a total of 320,000 women and their babies.

Nineteen hospitals have signed up to take part so far, with Royal Devon & Exeter, Nottingham University Hospitals and University Hospitals Plymouth being the first hospitals to start.

University Hospitals Plymouth will be the first to begin offering testing for GBS to pregnant women routinely as part of the trial this week.

One in four pregnant women carry GBS in their vagina and rectum and are unlikely to be aware they carry it. Mothers who do may expose their baby to the bacteria around labour and birth. While most babies who carry GBS remain well, there is a small chance the baby will become seriously ill or may even die.

This new trial, which is managed by the University of Nottingham Clinical Trials Unit, will look at whether testing pregnant women for GBS reduces the risk of infection in newborn babies. The current strategy in the UK, is to offer antibiotics during labour to women who are considered at increased risk of their baby developing a GBS infection.

Since 2000, there has been a rise of almost a third in the rate of GBS infections in babies under three months of age, despite these ‘risk-based’ prevention guidelines being introduced in 2003. Sixty-five per cent of UK newborn babies who develop GBS infections have mothers who had no risk factors and 70 per cent of women who have risk factors do not actually carry the bacteria and are therefore given antibiotics unnecessarily.

The trial will look at the effectiveness of two different tests- a test offered at 35 to 37 weeks of pregnancy, and a ‘bedside test’ offered at the start of labour.

The work is being led by Dr Kate Walker, Clinical Associate Professor of Obstetrics, and Professor Jane Daniels, Professor of Clinical Trials at the University of Nottingham’s School of Medicine.

We are delighted that the GBS3 trial has started at these hospitals. After a delay caused by the pandemic, we are excited to start this important trial which will answer vital questions around how best to prevent GBS infection in newborn babies. This is the first trial of its kind worldwide and the results will help to determine whether routine testing should be introduced in the UK.”
Dr Kate Walker, Clinical Associate Professor of Obstetrics

Professor Jane Daniels said: “Doctors, midwives, policymakers and parents all want to know whether routine testing will reduce GBS infections in babies and save lives. Through this trial, we hope to provide data that can be used to inform future pregnancy care policy in the UK.”

Group B Strep Support is a national charity working to stop group B Strep infection in babies. Founded in 1996 by Jane and Robert Plumb after their newborn son, Theo, died from GBS infection aged 17 hours. The charity works with families affected by GBS and campaigns for a better prevention of GBS infection in babies in the UK.

Jane Plumb, Chief Executive of the charity, said: "We welcome the news that the GBS3 trial has 19 sites signed up, and that pregnant women are being offered group B Strep tests. This trial will settle the debate on what is the best prevention policy against GBS infection in newborn babies for the UK, and we fully support its success."

Lucy's story

Lucy Kelly, 33, now based in Midlothian. Lucy gave birth to Florence in July 2018.

"Less than 24 hours after our daughter was born, we were told she had an infection count of over 140 and consequently needed a lumbar puncture. She was subsequently treated for suspected neo-natal meningitis caused by Group B Strep, a bacteria we had never heard of before her birth. We were incredibly lucky: our daughter recovered fully with no long term side effects. The team at the hospital was incredible and we will be forever grateful.

We later learnt that although many countries test for Group B Strep, private tests are typically the only option in the UK. Had we been informed about GBS, or even better, offered a test during pregnancy, we would have taken the test and been able to make a more educated decision about how to proceed with her birth. Nonetheless, because of our experience with Florence, rather than policy, we were able to choose how to give birth to our second daughter. These choices should be available to all parents.

These trials are an important step forward in reproductive healthcare and the impact will be far reaching, with lives being saved and parents being given more choice and control over their birthing plans."


Story credits

More information is available from Professor Jane Daniels in the School of Medicine at or

Charlotte Anscombe - Media Relations Manager - Faculty of Medicine and Health Sciences
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The University of Nottingham is a research-intensive university with a proud heritage. Studying at the University of Nottingham is a life-changing experience and we pride ourselves on unlocking the potential of our students. We have a pioneering spirit, expressed in the vision of our founder Sir Jesse Boot, which has seen us lead the way in establishing campuses in China and Malaysia - part of a globally connected network of education, research and industrial engagement. Ranked 103rd out of more than 1,000 institutions globally and 18th in the UK by the QS World University Rankings 2022, the University’s state-of-the-art facilities and inclusive and disability sport provision is reflected in its crowning as The Times and Sunday Times Good University Guide 2021 Sports University of the Year. We are ranked eighth for research power in the UK according to REF 2014. We have six beacons of research excellence helping to transform lives and change the world; we are also a major employer and industry partner - locally and globally. Alongside Nottingham Trent University, we lead the Universities for Nottingham initiative, a pioneering collaboration which brings together the combined strength and civic missions of Nottingham’s two world-class universities and is working with local communities and partners to aid recovery and renewal following the COVID-19 pandemic.

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