What is the study about?

Group B Streptococcus (also known as GBS, Strep B or group B Strep) is a common type of bacteria that normally causes no harm. In the UK, 1 in 4 pregnant women carry group B Strep in their vagina and rectum.

If a woman carries group B Strep, their baby may be exposed to it around labour and birth. While most babies won’t be affected, there is a very small chance of the baby becoming seriously ill or even dying. In extremely rare cases group B Strep infection can cause miscarriage, early labour or stillbirth.

Current UK practice is to offer antibiotics during labour when the baby is at higher risk of developing GBS infection based on maternal risk factors. The GBS3 trial is looking at whether routine testing of every pregnant woman and offering antibiotics to those who carry GBS, reduces the risk of infection in newborn babies compared to the current strategy in place in the UK.

There are two different tests, which we are comparing against the current risk factor based strategy.

• Lab Based Test at 3-5 weeks before anticipated delivery date (Enriched Culture Medium Testing)
• Bedside Test at start of labour (Intrapartum Rapid Testing)

71 maternity units will be involved across England, Scotland and Wales. Each hospital involved in GBS3 trial is randomly allocated to one of 2 testing groups or will continue undertaking the current strategy.  This means that all women who are pregnant and give birth at that hospital will be treated in the same way (unless advised otherwise by their doctor or midwife).

The study will use medical information routinely collected by the NHS about the woman’s labour and birth and the baby.

Who can take part in the study?

71 maternity units will be involved across England, Scotland and Wales. All pregnant women giving birth at 24 or more week’s gestation within their maternity unit’s recruitment period can be included in the data collection.

What is being tested in the study?

2 testing strategies for GBS:

• Lab Based Test at 3-5 weeks before anticipated delivery date (Enriched Culture Medium Testing)
• Bedside Test at start of labour (Intrapartum Rapid Testing)

What is this being compared to?

Risk factor based strategy

What are we trying to find out?

Whether routine testing of women for GBS colonisation either in late pregnancy or during labour reduces the occurrence of early-onset neonatal sepsis, compared to the current risk factor based strategy.

How many patients do we need?

71 maternity units will be involved to allow information on 320,000 women to be collected.

Funder

National Institute for Health and Care Research - Health Technology Assessment (NIHR- HTA)

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