UK Guidelines

This section includes key points for health professionals, highlighting the key information about group B Streptococcus (GBS or group B Strep) and the latest clinical guidelines (links at the bottom of the page to relevant guidelines). It includes:

• What to do about GBS during a woman’s pregnancy
• Who should be offered intravenous (IV) antibiotics in labour
• Which antibiotic to use (and which not to use)
• When to offer antenatal testing for GBS carriage
• What monitoring should be done after the baby is born
• Signs of infection to look out for

GBS is the most common cause of severe infection in newborn babies, and of meningitis in babies under age 3 months.

Most GBS infection is of early onset, presenting in babies within the first 6 days of life, and usually within the first 12 hours after birth. Between age 7 days and 3 months, these infections – described as late-onset – are rare. In babies over after age 3 months, they are very rare indeed.

Most early-onset GBS infections (in babies aged 0-6 days) could be prevented by giving intravenous antibiotics in labour to women whose babies are at raised risk of developing GBS infection. In the UK, women are offered IV antibiotics in labour is based on specific risk factors.

The Royal College of Obstetricians and Gynaecologists (RCOG) published a major update to their clinical guideline on preventing group B Strep infection, their Green-top Guideline (GTG) No 36 in September 2017. There are substantial changes from previous editions, and this section summarises the key recommendations and changes. (In brackets after each recommendation is the paragraph number to which it relates in the GTG.)

In January 2018, a patient information leaflet, co-written by the RCOG and GBSS, was published. E-copies are available from both organisations and hard-copies are available from GBSS free of charge to families and the NHS. Click here to read, download or order the leaflet.

Antenatal Care

1. During the woman’s pregnancy

• Provide all pregnant women with a patient information leaflet about group B Strep (GTG 4.1). A suitable leaflet has been co-written by the RCOG and GBSS. E-versions are available from both organisations, and hard copies (free to the NHS) from GBSS.
• Treat at diagnosis a woman with a GBS urinary tract infection (>105 cfu/ml) during pregnancy with oral antibiotics, and ensure she is also offered IV antibiotics in labour (GTG 6.1).
• Treating GBS carriage, detected from a vaginal or rectal swab, is NOT recommended before labour starts. The woman should be offered IV antibiotics when labour starts (GTG 6.2).

2. When is an offer of antenatal testing appropriate?

If a woman carried GBS in a previous pregnancy and the baby did not develop GBS infection, an Enriched Culture Medium (ECM) swab test for GBS carriage should be offered at 35-37 weeks (or earlier if preterm delivery is anticipated) (GTG 5.3).

The ECM test is different from the standard swab taken to investigate a vaginal discharge. For the ECM test, swabs should be taken both from the low vagina and rectum (GTG 9.1), with samples cultured using enriched culture media (9.3) and processed ASAP (GTG 9.2). You should specifically state ‘test for GBS’ on the request form (GTG 9.3).

If positive, the woman should be offered antibiotics in labour. If negative, she can be reassured that the risk of early-onset GBS infection in her baby is very low (about 1 in 5,000). If the woman chooses not to be tested, she should be offered antibiotics in labour (GTG 5.3).

3. Who should be offered antibiotics in labour?

A woman should be offered antibiotics effective against GBS in labour if she:

• had a previous baby who had GBS infection (GTG 5.4).
• had GBS in her urine during the pregnancy (GTG 7.1).
• had GBS detected on a vaginal or rectal swab (via an NHS or other test) during the current pregnancy (GTG 6.3).
• carried GBS in a previous pregnancy and has declined testing this pregnancy (see above) (GTG 5.3).
• is in preterm labour (before 37 completed weeks of pregnancy) (GTG 7.3).
• has a temperature of 38°C or greater (in which case, offer broad-spectrum antibiotics that also cover GBS) (GTG 7.2).

What should happen around labour and birth?

4. Which IV antibiotic should I use?

If the woman has agreed to have the IV antibiotics in labour, they should be given as soon as possible once labour has started, and at regular intervals until the baby is born (GTG 9.4).

• Benzylpenicillin (Penicillin G) is the antibiotic of choice, 3g given intravenously as soon as possible once labour has started and then 1.5g every 4 hours until the birth (GTG 9.4).
• In penicillin-allergic women, a cephalosporin should be used (e.g. Cefuroxime 1.5 g loading dose followed by 750 mg every 8 hours) unless she has had a severe allergic reaction (swelling of the skin or throat, difficulty breathing, and/ or fainting/low blood pressure), in which case, vancomycin (1g every 12 hours) should be used (GTG 9.5).
• Clindamycin is not recommended as the current resistance rate in the UK is high (GTG 9.5).

5. What should happen around labour and birth?

• Caesareans:
  • A woman having a planned Caesarean section doesn’t need IV antibiotics specifically for GBS, as long as her waters haven’t broken and she’s not in labour (GTG 6.6 & 7.3).
• Induction:
  • Carrying group B Strep doesn’t affect the method of induction – simply offer IV antibiotics as soon as labour is established (GTG 6.4).
• Membrane sweeps:
  • Carrying GBS does not mean that membrane sweeps are contraindicated (GTG 6.5).
• Prelabour rupture of membranes
  • A woman carrying GBS whose waters break at term should be offered IV antibiotics immediately, and induction of labour as soon as reasonably possible (GTG 7.1).
  • A woman not carrying GBS or whose GBS carriage status is unknown and whose waters break at term should be offered induction of labour immediately or at any time up to 24 hours after the waters broke, depending on her preference (GTG 7.1).
• Preterm rupture of membranes
  • Women whose waters break preterm (before 37 completed weeks) should be offered IV antibiotics once labour is confirmed or induced, regardless of whether or not they are known to carry GBS (GTG 8.1).
• Reactions to IV antibiotics in labour
  • Adverse reactions to IV antibiotics in labour are rare. They may include anaphylaxis (A UK Obstetric Surveillance System study (2012–2015) identified one case of maternal anaphylaxis following prophylactic use of antibiotics for GBS out of an estimated 2.3m maternities over 3 years).
  • Antibiotics given around labour may have an effect on the microbiome (bacterial flora) of the newborn baby which has been linked to a number of later effects in the child, including allergy, and obesity and diabetes, atlhough these risks remain theoretical. Measured effects so far are slight and probably temporary (up to three months) if penicillin is used (GTG 9.7).
• Vaginal cleansing
  • This is not recommended as there’s no evidence it reduces the risk of GBS infection in the newborn baby (GTG 10).
• Waterbirth
  • As long as IV antibiotics are offered in labour to a woman carrying GBS, labour or birth in water is not contraindicated (GTG 7.5).

Postnatal Care

6. After the baby is born:

• If a woman carrying GBS declined IV antibiotics in labour
  • her baby should be monitored very closely for 12 hours after birth, and Mum should be discouraged from very early discharge (GTG 9.6).
• If a mother carrying GBS gave birth at term and received IV antibiotics against GBS for over 4 hours before birth
  • her newborn baby doesn’t need any special observations, as the risk of GBS infection is very low (GTG 11.2).
• If a mother received broad-spectrum IV antibiotics in labour for reasons other than GBS
  • her newborn baby may still need investigation and treatment (GTG 11.2).
• If a mother has previously had a baby who developed GBS infection (GTG 11.6) OR had risk factors for early-onset GBS infection but did not receive more than 4 hours of IV antibiotics before birth (GTG 11.3)
  • her baby should be checked at birth for clinical indicators of infection, and their vital signs should be checked at 0, 1, and 2 hours old, then every 2 hours until 12 hours old.
• Babies without signs of early-onset GBS infection and without known risk factors
  • are at low risk of developing early-onset GBS infection and shouldn’t be given preventative antibiotics as routine (GTG 11.4).
• Babies showing signs of early-onset GBS infection
  • should be treated with penicillin and gentamicin within an hour of the decision to treat (GTG 11.5).
• Women should be encouraged to breastfeed
  • whether they carry group B Strep or not (GTG 11.7).

7. Signs of GBS infection to look out for in a newborn baby:

You can download our poster highlighting the most common signs of early-onset group B Strep infection in babies here.

Families should be encouraged to seek urgent medical attention if their baby (GTG 11.1):

• Is grunting, has noisy breathing, is not breathing at all, moaning, or seems to be working hard to breathe when you look at the chest or tummy
• Is very sleepy and/or unresponsive
• Has inconsolable crying
• Is unusually floppy
• Is not feeding well or not keeping milk down
• Has a high or low temperature, and/or their skin feels to be too hot or cold
• Has changes in their skin colour (including blotchy skin)
• Has an abnormally fast or slow heart rate or breathing rate
• Has low blood pressure (only identifiable by hospital tests)
• Has low blood sugar (only identifiable by hospital tests)

Other Guidelines

From this page, you can download the most recent UK guidelines relevant to group B Strep (this page is updated as guidelines are reviewed).