GBS – your questions answered

One in four women is a carrier of this hidden bug, which could harm your unborn baby.


Q What is GBS?

A It stands for Group B Streptococcus, a type of bacterial infection. It’s part of the same family of bugs associated with sore throats. GBS can come and go – a person does not have to be a carrier all her life.


Q What are the chances that I might have it?

A Roughly a quarter of women of childbearing age carry it harmlessly in their vagina or rectum, without any symptoms. However, only a small number of carriers – about one in 300 – have babies who develop GBS infection. It’s not known why.

Q How many babies are affected?

A In 2008, 421 proven cases in babies under 90 days old were reported in England, Wales and Northern Ireland. However, the real number is likely to be much higher.

Q At what stage might it be passed on to the baby?

A Babies are usually exposed to GBS just before or during the birth. Up to 80% of GBS infections in babies develop in the first two days of life. Once the baby reaches 3 months, GBS infection is extremely rare.

Q How serious is it for a baby?

A In the UK, around 75 babies die every year from GBS or complications of it, such as meningitis, pneumonia and septicaemia (blood poisoning). A further 40 suffer long-term problems, from mild learning disabilities to severe mental problems, blindness and deafness. GBS is also a rare cause of premature delivery, stillbirth and late miscarriage.

Q How do I find out if I’m a carrier?

A swab test is available from two private laboratories – The Doctors Laboratory  and the Mullhaven Medical Laboratory, for £32. This is best performed at 35 to 37 weeks and you can either take the swab yourself, or ask your midwife or doctor to do it for you (they may charge for this). You’ll have to fill in a request form in conjunction with your midwife or doctor, then send the swab to the lab for analysis. The private labs use a test called the Enriched Culture Medium (ECM) method, which is known to be highly reliable.

Q Can’t I get a test on the NHS?

A The NHS doesn’t routinely test for GBS, although you can specially request a test. However, they usually use a test called the High Vaginal Swab (HVS) method, which is known to be much less reliable than the ECM test used by the private labs


Q If I’m a carrier, can I reduce the risk of my baby getting it?

A Yes. If you’re treated with intravenous (in a vein) antibiotics during labour and birth, your baby’s risk of developing GBS drops significantly, to less than one in 6,000.


For more informa visit  Group B Strep Support at

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