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A bit about Group B Strep

Being told you have tested positive for Group B Strep, or perhaps just hearing about it's existence, can be scary for many expectant parents. This blog post seeks to provide you with some information and signposting to further resources. As with everything on this website it is not advice, instead I hope it sheds some light on the basics of Strep B, testing and your choices.

It's a bacteria called Streptococcus agalactiae. Perhaps mostly commonly known as group B strep, but also as group B streptococcus, GBS and sometimes referred to as beta strep or haemolytic strep.

GBS bacteria is very common with 20% to 40% (depending on where you live!) of women having it present in their bodies at some time. Being a ‘carrier' of GBS, does not necessarily mean you have an active ‘colony’ of the bacteria now – GBS can come and go. The bacteria lives in the gut (including rectum – the bottom) and/or the vagina. Most people will be unaffected by the presence of the bacteria. In fact, the majority of people with GBS will have no idea they have it, in the UK there’s no routine testing for it. Often people will only know they have had it, if they have had something like a suspected UTI, or vaginal infection (symptoms like unusual discharge, itching etc) or another gynaecological issue where they have been given a vaginal swab test. Unfortunately, people are not always given full information on what swabs are testing for and the potential consequences of having such results on their medical history. They may very unfortunately have been tested without their consent. Whenever you consent to any vaginal swabs in pregnancy or prior to a pregnancy, it can be a good idea to ask exactly what is being tested for, and perhaps note it down. So sometimes people will have no idea they have been tested for GBS, let alone tested positive for GBS presence until they become pregnant and find that there’s a historical test result on their records. For a more up to date test some people decide to test privately due to lack of NHS offers or resources: there’s more info here & you can order one kind of test often for around £40

If you are being offered in labour antibiotics because you once had a positive GBS it may well be worth considering asking for NHS testing or private testing 2-3 days prior to the most likely time you are due to go into labour, this can of course be tricky due to the unpredictability of labour starting. There are several different types of GBS test some faster than others and some available, some not under different trusts. For many people having a more recent test, even if not exactly in the labour time scale can be reassuring & help in making decisions as to the care offers they accept and decline.

“Some women who have a risk factor or who have found they carry GBS decide to do nothing except keep a close eye on their baby once she or he is born; especially during the first 24 hours when EOGBS disease is most likely to manifest. Other women decide to have the intravenous antibiotic prophylaxis offered within systems of maternity care, while others use alternative approaches in an attempt to remove or reduce harm from any GBS bacteria.” Wickham, Sara. Group B Strep Explained (pp. 69-70). Birthmoon Creations. Kindle Edition.

The GBS bacteria can be described as commensal – it does not generally do anything helpful or harmful to the adult carrier. However, in pregnancy the primary concern of health care professionals is the potential of GBS to cause problems if the bacteria passes to the baby which has the potential to make some young infants very ill. Maternity services’ offers of interventions regarding GBS in pregnant people, are an attempt to avoid cases of Early-onset neonatal Group B Streptococcus (EOGBS) disease.

“What could GBS mean for my baby?

Many babies come into contact with GBS during labour or around birth. The vast majority of these babies will not become ill. However, if you carry GBS, there is a small chance that your baby will develop GBS infection and become seriously ill, or even die.

Around 1 in every 1750 newborn babies in the UK and Ireland is diagnosed with early-onset GBS infection. The infections that GBS most commonly causes in newborn babies are sepsis (infection of the blood), pneumonia (infection in the lungs) and meningitis (infection of the fluid and lining around the brain).

Although GBS infection can make your baby very unwell, with prompt treatment most babies will recover fully. However, of the babies who develop early-onset GBS infection, 1 in 19 (5.2%) will die and, of the survivors, 1 in 14 (7.4%) will have a long-term disability. On average in the UK, every month:

• 43 babies develop early-onset GBS infection

• 38 babies make a full recovery

• 3 babies survive with long-term physical or mental disabilities

• 2 babies die from their early-onset GBS infection.”

The offer of preventative treatment aka prophylaxis – is administering prophylactic antibiotics during labour via a drip. The prophylactic antibiotics can affect the choices of your place of birth, your birth experience physically & mentally & your body’s health in relation to the effect of antibiotics on your gut health e.g. increased antibiotic resistance, an increase risk of infections such as thrush & an upset tummy or in very rare circumstances a reaction to the antibiotics etc. The antibiotics also enter your baby’s bloodstream. For a full look at the risks of the antibiotics take a look at ‘The risks of antibiotics’ - Wickham, Sara. Group B Strep Explained (p. 89). Birthmoon Creations. Kindle Edition.

It’s interesting to know that “GBS bacteria can occasionally cause a urine, uterine (womb) or other infection in women, but serious GBS disease in pregnant women is rare. A UK study found that serious GBS disease affected only 1 in about 27,000 women and that 79% of babies born to women who experienced severe sepsis, a life-threatening consequence of infection, did not themselves develop sepsis (Kalin et al 2015).” Wickham, Sara. Group B Strep Explained (pp. 6-7). Birthmoon Creations. Kindle Edition.

Extra risk factors associated with illness in baby include:

“What puts my baby at higher risk of developing GBS infection?

Infection is more likely to happen if:

• your baby is born preterm (before 37 completed weeks of pregnancy) – the earlier your baby is born, the greater the risk

• you have previously had a baby affected by GBS infection

• you have had a high temperature or other signs of infection during labour

• you have had any positive urine or swab test for GBS in this pregnancy

• your waters have broken more than 24 hours before your baby is born."

“GBS testing is not routinely recommended in countries such as the UK and New Zealand, because a different approach to determining risk is used.

Neonatal GBS disease

We have already established that GBS is a bacterium which a percentage of people carry in their bodies and that, while we don’t think it offers any particular advantage to the carrier, it is usually not considered harmful or unhealthy. I have also explained that GBS can exist in the vagina or rectum (among other places) and so, when a woman who carries GBS becomes pregnant and gives birth, the GBS bacteria can sometimes be transferred to her baby during labour and birth. Most of the time this is not a problem, and every day thousands of women with GBS in their vaginas and/or rectums give birth to healthy babies. Emphasis added by me – sometimes this such as crucial point for birthing people to consider when making decisions about their care, which is often not mentioned by health care professionals. Wickham, Sara. Group B Strep Explained (pp. 16-17). Birthmoon Creations. Kindle Edition.

Special Circumstances, such as ‘group B strep’ trigger special offers from health care professionals of interventions in your pregnancy and birth from testing to treatments. It can be so difficult to decide on whether to accept an intervention or decline one. Every birthing person has to make a unique decision based on their own unique circumstances, personal needs and preferences. The decision-making acronym BRAINS can be helpful when weighing up what’s the unique best course of action for you:

Benefits – what are the benefits to accepting an offer – in this case of a test in itself and/or intravenous antibiotics during labour if a test result has been positive?

Risks – what are the risks to you and your baby of accepting the IV antibiotics?

Alternatives – Do you know if you are currently positive for GBS? If yes, and if you felt the need - what other methods of prophylactic treatment?

Intuition – what is your gut feeling telling you?

Nothing – what is most likely to happen if you did nothing? If you did not have a test or if you didn’t take IV antibiotics?

Second - opinions/stories have you asked another health care professional, or sought information out from evidence-based sources? Are there birth stories from people with similar circumstances out there that might inspire or reassure you?


Essential read for anyone wishing to have evidence based info explained and analysed clearly, at their finger tips (also on kindle) – including ‘alternative/holistic’ prophylactic treatments Group B Strep Explained By Sara Wickham 2019 Birthmoon Creations,aps,151&sr=8-5-fkmrnull&linkCode=sl1&tag=sarawickham-21&linkId=a7e1784cd2d056fae5ad37f3762b1dc5&language=en_GB

You can order a test here if required and there’s also lots of info available on other aspects of GBS and pregnancy & birth:

Though a slightly out of date resource in some respects this has some excellent positive stories specific to GBS & Homebirth

Group B Strep Support (GBSS):

RCOG Green-top Guideline No. 36, Prevention of Early-onset Neonatal Group

NICE clinical guideline CG190, Intrapartum Care for Healthy Women and Babies:

NICE clinical guideline CG149, Neonatal Infection (Early Onset): Antibiotics for Prevention and Treatment:

UK National Screening Committee, recommendation on GBS screening in pregnancy:

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