Group B Streptococcus (GBS or Group B Strep)) is a natural bacteria carried in around 30% of UK adults. It is not a sexually transmitted disease, it lives naturally in the vagina and rectum (back passage), has no symptoms and its presence/carriage can come and go. A urine infection with GBS indicates a high level of carriage and is treated with oral antibiotics in the pregnancy.

Although an infection with GBS in babies is relatively uncommon, it can be very serious. Most newborn babies who are ill with a GBS infection recover completely with good medical care. However, one in ten of those infected dies, usually of septicaemia, pneumonia or meningitis, and at least one in twenty suffer long-term problems. After the age of 3 months GBS infection is very rare.

If the mother is carrying GBS infection at the time of birth the risk of her baby developing a GBS infection is one in 300.

In the UK the Royal College of Obstetricians and Gynaecologists (RCOG) currently recommends offering women intravenous antibiotics in labour if they have certain “risk factors” for infection, such as:

  • GBS has been detected from a vaginal swab or urine sample during the current pregnancy
  • Mum has previously had a baby who had a GBS infection
  • Mum has a high temperature in labour

An Enriched Culture Medium (ECM) “gold standard” test on a rectal and vaginal swab is highly effective at detecting GBS carriage and for predicting carriage status for the 5 weeks after the swabs are taken. Most NHS Trusts use an “all purpose” medium for their swabs, which only detects 50% of the women who carry GBS at the time the test is taken.

The RCOG does not recommend routine screening for all pregnant women in the UK for GBS carriage. In many countries (such as USA, Canada, France, Spain, Germany) routine screening for GBS in pregnancy is carried out and the charity Group B Strep Support has been campaigning for some time for this practice to be brought into the UK.

Whilst most babies born to mothers carrying GBS will not become infected, for those who do it can be very serious, indeed life-threatening.

Until a time when all pregnant women are offered screening for GBS I believe it is important that expectant couples are given accurate information about GBS and allowed to make an informed choice for themselves about whether they wish to choose private screening.

If you wish to find out more about this topic please visit:

Screening for GBS by self-taken rectal and low vaginal swabs are ideally taken at 35-37 weeks of pregnancy and cost about £35 to be tested by “gold standard” ECM.