What is Group B Strep?

Chance are you've never heard of Group B Streptococcus – although that may change in the future, as soon all pregnancy women will be given a special information leaflet about it. Also known as Strep B or GBS, it's a so-called 'friendly bacteria' up to a third of us carry in our gut and it's thought to play a role in digestion.


However, a quarter of women of childbearing age also find it lurking down there. Yep, it can live in your vagina too (or colonise, as the doctors like to describe it). It's not a sexually transmitted disease though.

“The reason it gets into the vagina is simply because of female anatomy," says Prof Philip Steer, consultant obstetrician at Chelsea and Westminster Hospital. "The rectum and vagina are pretty close.”

Is it Group B Strep dangerous?

Yes and no.

It's rarely harmful if you're not pregnant and you are unlikely to show any signs or symptoms. The downside of this is that you'll never know you are a carrier.

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And this causes problems when you do become pregnant. GBS has been linked to late miscarriage, preterm birth, stillbirth and maternal infection.

It can also pass to your baby during labour and birth, meaning she is colonised too. In some cases, this leads to an infection, with premature babies particularly prone as their immune systems are less developed.

“GBS is the primary cause of bacterial infection in newborn babies and there’s been a gradual drift up in the number of cases,” says Prof Steer. According to the Royal College of Obstetricians & Gynaecologists, 1 in 1,000 newborn babies in the UK is diagnosed with a GBS infection.

Before you start to panic, although this can make babies very poorly, most do make a full recovery. However it is thought that 1 in 10 newborns who catch it are left with a life-long disability. This could be anything from mild learning difficulties to severe mental retardation, loss of hearing or sight, or lung damage.

Sadly one in 16 sufferers will not survive.

How do I know if I'm a carrier?

As there are no symptoms, Group B Strep is usually only detected when you’re swabbed for something else such as abnormal discharge. “I had a urine infection and when they sent the sample off to the lab to be grown to make sure I was on the right antibiotics, this also grew,” says macdoona

The US and many European countries offer a vaginal swab test for Group B Strep in pregnancy, between 35 and 38 weeks. If the result is positive, the women are offered intravenous antibiotics during labour to reduce the risk of it passing onto their baby. This is more effective that treating the baby afterwards.

However, the NHS does not routinely screen mums-to-be. If you want a test, you have to do it privately, at a cost of about £40.

Otherwise, doctors and nurses will attempt to identify risk factors or signs that you are a carrier, such going into early labour, ruptured membranes and a raised temperature. In such cases, you will be offered intravenous antibiotics in labour, even if haven't had a positive test (there may not be time for a test or, if there is, to wait for the results, as they can take 48 hours).

I’ve got it: what happens next?

As milliysmum_naomi recalls: "I had the big yellow stickers all over my notes as if I had some infectious disease!" It might sound embarrassing but this is to make sure medics know you need antibiotics and to watch for signs of infection in your baby.

"If you take a normal, pregnant woman carrying GBS at delivery, the chances of her baby developing a GBS infection where no preventative medicine is being given is around 1 in 300," explains Jane Plumb, who set up the charity Group B Strep Support after losing her own baby to the infection. "If the same woman has intravenous antibiotics in labour, the risk drops to smaller than 1 in 6,000."

Smithya85 says: “It sound scary at first but it really isn’t! In fact you’re actually lucky that like me you know you have it before giving birth. You keep the drip in right though labour and they give you antibiotics through it every 4 hours. I personally didn’t like having the drip in but it’s not the end of the world."

If it's so risky, why aren’t British women screened?

The main reason that mums-to-be aren't tested is that many thousands who carry the bacteria will not pass it on to their babies. If every carrier was given antibiotics in labour, it would mean treating around 150,000 women each year.

There is much debate about whether this is the right thing to do, especially at a time when antibiotic resistance is rising.

Dr Chris Steele, resident doctor on ITV's This Morning and patron of Group B Strep Support, says: “Group B Strep is the most common cause of severe infection in newborn babies, and of meningitis in babies’ first two months.

"All pregnant women should be able to make an informed choice about what they want to do, including the option of testing. It could save a baby’s life.”

But some argue that mums could suffer a possible allergic reactions to antibiotics, while the gut flora of babies who receive them in the womb might be affected.

Anne Mackie, director of programmes for the UK National Screening Committee, says: "The UK NSC found that the current recommended test for GBS carriage cannot reliably identify those women who would have an affected baby.

"This could result in a large number of women unnecessarily receiving intravenous antibiotics during labour, and there are potential risks associated with this”.

How do I get a test if I'm worried?

There are two ways of testing for GBS: home testing (often sold in pharmacies) and the swab test offered by the NHS. The swab test or Enriched Culture Method (ECM) is more reliable.

The ECM is not widely available or routinely offered on the NHS, despite being used in many countries around the world. However, it is possible to take an ECM privately for less than £40.

You can order an ECM Group B Strep test called Strepelle for £39.99, which is recommended for use from week 35. It contains:

  • two swabs
  • full instructions
  • a pre-paid envelope to send to the lab

You'll receive the results 3 days after the lab has received your swab sample, and you can choose whether to get results either by letter, text, or email. If it turns out you are a carrier, you simply let your doctor or midwife know, and you'll be given antibiotics intravenously during labour.

Can I still have a home birth if I have Group B Strep?

It is unlikely. If you’ve definitely got GBS, you’ll be hooked up to a drip and given intravenous antibiotics every four hours during labour, although sometimes this can be done at home.

What about a water birth?

Some hospitals’ policies state that women known to carry GBS should avoid a water birth - there are sometimes concerns around keeping the cannula site (where the needle goes in) dry.

However, there are many that don’t see it as a problem and, in report produced by Group Strep B Support called,Water birth for women with GBS: a pipe dream,it states: “No published evidence supports denying these women the water labour and birth they want."

MFMer Laranchloe says, “I had group b strep when pregnant but I ended up with an elective c-section. I was told that water births were out because I would need to be on a drip and therefore not allowed in the water and also in my area they wanted me in asap because of the Group B Strep in case I progressed quickly, but…check with your mw or hospital on their own policy”.