Within this information, we may use the terms "woman" and "women". However, we recognise that not only people who identify as women may want to access this content. Your care should be personalised, inclusive and sensitive to your needs, whatever your gender identity.
Group B streptococcus (also known as group B strep, strep B, beta strep and GBS) is a type of bacteria which lives in the intestines, rectum and vagina of around 20 - 40% of women in the UK. This is often referred to as "carrying" or being "colonised with" GBS.
GBS can cause infection in very young babies and, very rarely, during pregnancy, before labour begins.
It is important to understand that group B strep is not a sexually transmitted disease. Most women carrying GBS will have no symptoms. Carrying GBS is not harmful to you, but it can affect your baby around the time of birth.
- Group B strep is one of the many bacteria that live in our bodies and which usually cause no harm
- Testing for GBS is not routinely offered to all pregnant women in the UK
- If you carry GBS, most of the time your baby will be born safely and will not develop an infection. However, in rare cases, it can cause serious infection such as sepsis, pneumonia or meningitis
- Most early-onset GBS infections (those developing in the first week of a baby's life) are preventable
- If GBS is found in your urine, vagina or rectum (inside your bottom) during your current pregnancy, or if you have previously had a baby affected by GBS infection, you should be offered antibiotics in labour to reduce the small risk of this infection to your baby
- IfGBS was found in a previous pregnancy and your baby was unaffected, you can haveaspecificswabtesttoseewhetheryouarecarryingGBS when you are 35 - 37 weeks pregnant
- If the test result is positive, you will be offered antibiotics in labour
- If the test result is negative, the risk of your baby developing early-onset GBS infection is low and you may choose not to have antibiotics
- The risk of your baby becoming unwell with GBS infection is increased if your baby is born earlier than 37 weeks, if you have a temperature while you are in labour, or if your waters break before you go into labour
- If your newborn baby develops signs of GBS infection, they should be treated with antibiotics straight away, which can mean a stay of up to 5 days in hospital. Your baby will have a small cannula in the hand and be given IV antibiotics
- this will be put as an ALERT on your maternity records so the obstetric team are aware and can give you the correct care
- you should also let the maternity team know if you arrive at the hospital in labour
- you must come into hospital immediately if your waters break, and advise our staff that you are GBS positive
How do I get group B strep?
Like many bacteria,GBS may be passed from one person to another through skin-to-skin contact, for example:
- hand contact
- close physical contact
As GBS is often found in the vagina and rectum of colonised women, it can also be passed through sexual contact. However, GBS is not a sexually transmitted disease, and GBS carriage is not a sign of ill health or poor hygiene.
- There are no known harmful effects of carriage itself and the GBS bacteria do not cause genital symptoms or discomfort
- No-one should ever feel guilty or dirty for carrying GBS – it’s completely normal
Everyone, regardless of whether they know they carry GBS, should wash and dry their hands properly before handling a newborn baby.
How is group B strep found? How do you test for it?
Most women carrying GBS have no symptoms, so it's often found by chance through a vaginal or rectal swab test, or a urine test.
The NHS does not routinely test all pregnant women for group B strep.
Tests designed specifically to find GBS carriage, known as the enriched culture medium (ECM) test, are increasingly becoming available within the NHS and are widely available privately.
What could group B strep mean for my baby?
Many babies come into contact with group B strep during labour, or during or after birth and the vast majority will not become ill.
However, there is a small chance that your newborn baby will develop group B strep infection, and this chance is increased if you are carrying GBS.
Although group B Strep infection can make your baby very unwell, and unfortunately in some rare cases can be fatal, with prompt treatment most babies will recover fully.
- The infections that group B Strep most commonly causes in newborn babies are:
- sepsis (infection of the blood)
- pneumonia (infection in the lungs)
- meningitis (infection of the fluid and lining around the brain)
- Around 1 in 1,750 babies in the UK and Ireland is diagnosed with early-onset group B Strep infection (developing in babies aged 0 - 6 days)
- Around 1 in 2,700 babies in the UK and Ireland is diagnosed with late-onset group B Strep infection (developing in babies aged 7 - 90 days)
- Of the babies who develop GBS infection, 1 in 19 (5.2%) will die from early-onset GBS infection and 1 in 13 (7.7%) from late-onset GBS infection
- Of those who survive their GBS infection, 1 in 14 (7.4%) will have a long-term disability following early-onset GBS infection and 1 in 8 (12.4%) following late-onset GBS infection
Is my baby at risk of group B strep infection?
Any baby can develop a group B Strep infection, but early-onset group B Strep infection (developing in the first 6 days of life, and usually on the first day of life) is more likely if:
- your baby is born earlier than 37 weeks of pregnancy – the earlier your baby is born, the greater the risk
- you have previously had a baby who developed a group B Strep infection
- you have had a high temperature (or other signs of infection) during labour
- you have had any group B strep-positive urine or swab tests in this pregnancy
- your waters have broken more than 24 hours before your baby is born
Late-onset group B Strep infection (developing in babies aged 7 - 90 days) is less common than early-onset GBS infection and is more likely if:
- your baby is born earlier than 37 weeks of pregnancy
- you have had a group B strep-positive test in this pregnancy
How can the risk to my baby be reduced?
Most early-onset group B strep infection can be prevented by giving intravenous antibiotics in labour to women whose babies are at raised risk of developing the infection. At present, there are no known methods to prevent late-onset GBS infection.
- A urine infection caused by group B Strep should be treated with antibiotic tablets straight away and you should also be offered intravenous (IV) antibiotics during labour
- You should be offered IV antibioticsduringlabourifyouhavehadaGBS-positive swab or urine test from an NHS laboratory or other accredited laboratories
- If you have previously had a baby who was diagnosed with GBS infection, you should be offered IV antibiotics when you are in labour
- IfGBS was found in a previous pregnancy and your baby was unaffected, you can have a specific swab test (knownastheECM test)toseewhetheryouarecarryingGBS when you are 35 - 37 weeks pregnant
- If the test result is positive, you will be offered antibiotics in labour
- If the ECM test result is negative, the risk of your baby developing early-onset GBS infection is low and you may choose not to have antibiotics
- If your waters break after 37 weeks of yourpregnancyandyouareknowntocarryGBS, you will be offered induction of labour straight away
- This is to reduce the time that your baby is exposed to GBS before birth
- You should also be offered IV antibiotics
- Even if you are not known to carry GBS, if you develop any signs of infection in labour, you will be offered IV antibiotics that will treat a wide range of infections, including GBS
- If your labour starts before 37 weeks of your pregnancy, your healthcare professional will recommend that you have IV antibiotics, even if you are not known to carry GBS
If you are worried about your baby, please contact your healthcare professional immediately, and mention any history of GBS.
How will my baby be monitored after birth?
- If your baby is born at full term (after 37 weeks of pregnancy or later) and you received IV antibiotics in labour at least 4 hours before giving birth, no special additional monitoring for group B strep is routinely recommended after birth
- If your baby is considered to be at higher risk of group B strep infection and you did not get IV antibiotics at least 4 hours before giving birth, your baby will be monitored closely for signs of infection for at least 12 hours. This will include assessing your baby’s general well-being, heart rate, temperature, breathing and feeding
- If you have previously had a baby who developed group B strep infection, your baby will be monitored for 12 hours, even if you had at least 4 hours of IV antibiotics in labour before giving birth
- After the baby is 12 hours old, the chance of your baby developing group B Strep infection is very low and neither you nor your baby will need antibiotics unless you or your baby becomes ill
Parents should be alert for any signs that could mean the baby is developing infection, and raise any concerns with their healthcare professional immediately.
Can I still breastfeed?
Yes, it is safe to breastfeed your new baby. Breastfeeding has not been shown to increase the risk of GBS infection, and it offers many benefits to both you and your baby.
How can I reduce the risk of my baby developing a group B Strep infection after they're born?
There are no known ways to prevent group B strep infection after a baby is born. Knowing the typical signs infections in young babies is essential. Early treatment is key.
Most babies will not develop a group B strep infection, though it is important to be aware of what the signs of this infection are, and when to take action.
Good hygiene measures are important for a young baby and, since group B strep may be carried on the skin, everyone should wash and dry their hands properly before handling a baby during the first three months of its life.
What are the signs of GBS infection in my baby?
Most babies who develop GBS infection become unwell in the first week of life, usually within the first 12 - 24 hours after birth. This is commonly known as early-onset GBS infection.
However, less common, late-onset GBS infection can affect your baby up until they are 3 months old. Having antibiotics during labour does not prevent late-onset GBS.
Babies with early-onset GBS infection may show the following signs:
- Grunting, noisy breathing, moaning, seeming to be working hard to breathe when you look at their chest or tummy, or not breathing at all
- Very sleepy and or unresponsive
- Crying inconsolably
- Unusually floppy
- Not feeding well or not keeping milk down
- A high or low temperature and/or their skin feels too hot or cold
- Changes in their skin colour, including blotchy skin
- An abnormally fast or slow heart or breathing rate
- Low blood pressure
- Low blood sugar
If you notice any of these signs (your baby does not have to have them all) or you are worried about your baby you should urgently contact your healthcare professional or go to your nearest A&E department. If your baby has GBS infection, early diagnosis and treatment is important, as delay could be very serious or even, in rare cases, fatal.
Treating GBS infection in babies
GBS infection needs to be treated promptly. Hospital staff would usually treat the infection with high doses of intravenous (through a vein) antibiotics.
The majority of babies with GBS infection can be treated successfully with penicillin, although some will require all the expertise of a neonatal intensive care unit.
If a baby develops GBS infection and is one of a multiple birth, the same antibiotics should be given intravenously to the other baby/babies as a preventative measure, even if they appear well.
A baby who has recovered from a GBS infection is at low but slightly increased risk of re-infection (estimated to be around 1 - 3%). There is no established evidence to recommend any specific treatments to prevent recurrent GBS.
If you would like to know more about GBS, please visit the Group B Strep Support (GBSS) website. GBSS is the world’s leading charity working to eradicate group B Strep infection in babies.
The GBSS confidential helpline provides information and support, and answers your questions.
Source and acknowledgements
Some of the information on this page is based on information supplied by Group B Strep Support.
Last reviewed: 28 February 2023