What is Group B Strep?

This bacteria lives in the intestines, rectum, and vagina of 20-40% of women in the UK . Group B Streptococcus is also known as Group B Strep, Strep B, or GBS. Most women have no symptoms and although it is not a sexually transmitted disease it can be passed from one person to another through close physical contact.

The importance of testing for Group B Strep in Pregnancy

GBS is not harmful to you as a carrier, most of the time your baby will be born safely but it can be passed onto your baby during birth.  This can occasionally cause serious infection such as Sepsisan infection of the blood, Meningitisan infection of the fluid and lining around the brain, or Pneumoniaan infection of the lungs in young babies and, very rarely, during pregnancy before labour.

Pregnant? Do you know about Group B strep?

If GBS is found during your pregnancy, or you have previously had a baby affected by GBS infection, you should be offered antibiotics in labour.  This reduces the risk of your baby contracting the infection.


Any baby can develop a Group B Strep infection. This can make your baby very unwell, BUT with prompt treatment most babies will fully recover.  However, early-onset Group B Strep infection which can develop in the first 6 days of life, usually on the first day of life is more likely if your baby is born preterm, if you have a temperature while in labour, or if your waters break before going into labour.  If your newborn baby develops signs of GBS infection, they should be treated with antibiotics straight away.

1 in 19 babies who develop a Group B Strep infection will die from early-onset GBS infection.

Late-onset Group B Strep infection can develop in babies between 7-90 days and although much less common than an early-onset GBS infection it is more likely if your baby is born before 37 weeks of pregnancy or you have had a positive Group B Strep test in your pregnancy.

1 in 13 babies that develop a GBS infection will die from late-onset GBS infection.

1 in 19 newborn babies who develop Group B Strep infection will die from the infection



1 in 14 of the babies who survive a GBS infection will have a long-term disability following their early-onset GBS infection and 1 in 8 following their late-onset GBS infection.



You should be offered antibiotics if you develop a urine infection associated with Group B Strep during your pregnancy and IV antibiotics again during labour. IV antibiotics should also be offered during labour if you have had a positive GBS test result or previously had a baby affected by GBS. If you are a known carrier of GBS and your waters break after 37 weeks you should be offered an induced labour to reduce the time your baby is exposed to GBS before birth along with antibiotics.  If you develop any signs of infection in labour such as a high temperature you should be offered IV antibiotics whether you are a known GBS carrier or not.

After birth make sure you, your partner and family and friends are all aware of the symptoms of a GBS infection.
Know the symptoms of Early-onset GBS infection
Contact your healthcare team urgently if you are worried about your baby and make sure you mention your GBS history.