October 15, 2019


Group B Strep is the most common cause of life threatening infection in newborns & meningitis in babies up to 3 months in the UK and yet 41% women have never heard of it. Routine antenatal screening of all pregnant women for GBS is not recommended by the UK National Screening Committee nor the Royal College of Obstetricians & Gynaecologists. It is however in countries such as Australia, Argentina, Belgium, Canada, Chile, Czech Republic, Dubai, France, Germany, Hong Kong, Italy, Japan, Kenya, Lithuania, New Zealand, Oman, Poland, Spain, Slovenia, Switzerland and the USA.
The UK charity, Group B Strep Support believes all pregnant women should be informed about group B Strep and offered the opportunity to have a sensitive test for the detection of GBS carriage late in pregnancy (35-37wks). So let’s discuss some of our most frequently asked questions explaining the Who, What, Where, When and Why of group B Strep…although not necessarily in that order.

1) What IS group B Strep? We get a fair number of calls and emails from women and their partners who fear GBS to be a disease, a lifetime diagnosis and/or a virus.

    • a.        Actually, group B Streptococcus is a natural and normal bacterium that colonises in 30% of all adults (men and women) without symptoms or side-effects. It is most commonly found in the intestines as part of your normal and friendly ‘gut’ flora. It is also found in the vagina living as a ‘commensal’ – an organism which lives on another without causing any harm. GBS can, however, occasionally cause infection, most commonly in newborn babies which can lead to septicaemia, pneumonia, and meningitis.


    b.        What it is NOT: GBS is not a sexually transmitted disease. Carrying GBS does not require treatment of the woman or of her partner and treatment does not prevent re-colonisation anyway.

2) “My Dr/Midwife says testing is not recommended and not to worry, so why get tested?”

    • a.        True. In lieu of testing, they recommend a ‘risk factor’ approach to determine which babies are more likely to develop group B Strep infection. These risk factors include Mum carrying GBS this pregnancy, high temperature during labour, labour starting or waters breaking prematurely and having previously had a baby infected with group B Strep.


    • b.        That being said, clinical risk factors are not accurate predictors of group B Strep infection in babies as 4/10 of the newborn babies who develop group B Strep infection have NO known risk factors. 5/10 newborn babies who die from group B Strep infection also had no known risk factors.


    c.        So why test? Why not?! With infections as serious as those caused by GBS, prevention is so much better than treatment! Knowing the result of a test sensitive for GBS test is always good news. If it’s positive, although it does mean that the baby is at a raised risk of developing GBS infection, it also means that – as the GBS carriage has been identified – simple, straightforward steps can be taken which have been proven to be extremely effective at minimising that risk.

3) Okay, I want a test. Where do I go? What do I ask for? When should I have it?

    • a.        Please know that even though routine testing is not recommended, you can still ask for one from your NHS or you can also request a private home test. Speak up. 35-37 weeks is suggested for testing, as this has shown to be a highly predictive indicator of whether you will be carrying when you go into labour. There are 3 different kinds of tests so it is important to know what is being offered. There is the Standard Direct Plating method which is the conventional NHS test, the ECM or Enriched Culture Medium method recognised as the gold standard for detecting GBS, and the Polymerase Chain Reaction method which is not widely available in the UK. While a handful of hospitals do offer the ‘gold standard’ ECM test, if yours does not there is a home-testing pack that is available privately for around £35.

b.        Are the tests accurate? … It depends.

      1. a.        A positive result from Standard Direct Plating (HVS), the conventional NHS test, is highly reliable, but a negative one is not. Only around 50% of women who are carrying GBS when the swabs are taken will correctly be told they carry GBS – the other half will be incorrectly told they are not. So trust a positive direct plating result, but be wary of a negative one.

b.        The ECM test is considered the gold standard for detecting GBS. The test is highly sensitive and if performed within 5 weeks of delivery, a negative result is 96% predictive of not carrying at delivery and a positive result is 87%.
4) “The test came back positive, now what? What is the chance of my baby becoming infected? ”
a.        Remember, knowing you are a carrier is good news because now you can take the appropriate preventative measures. Any positive GBS test result during pregnancy means that the pregnant woman should be offered intravenous antibiotics (Pencillin or, for women who are allergic to penicillin, there are alternatives) from the start of labour or waters breaking and then usually at 4 hour intervals until delivery. Intravenous antibiotics given in labour to mums carrying group B Strep reduce infection in babies by 90%!
b.        As for the chance of a baby becoming infected, there is a 1/300 chance if Mum is a carrier and no preventative antibiotics are given. There is a 1/6000 if Mum is a carrier and has the appropriate preventative antibiotics in labour.

If you’ve never before heard of group B Strep then you may still have tons of questions, understandably as it can be a lot to take in at first. Hopefully, though we’ve laid a solid foundation here upon which you can build your understanding and group B Strep awareness.

A helpful way to keep all this information in perspective is to remember M.U.M.M.Y:
M – many women carry group B Strep naturally
U – usually causes no problems, but can be devastating
M – most common cause of serious infection in newborns and meningitis in babies < 3 mo
M – most group B Strep infections in babies are preventable
Y – your knowledge can help protect your baby

Group B Strep Support (GBSS) is a UK charity, founded in 1996. Our three main aims are to:  Offer information and support to families affected by group B Streptococcus; Inform health professionals and individuals how most group B Strep infections in newborn babies can be prevented; and Generate continued support for research into preventing group B Strep infections in newborn babies.

Please visit our website for more information: www.gbss.org.uk | info@gbss.org.uk

Leave a Reply

Your email address will not be published. Required fields are marked *