Group B Streptococcus is the UK’s most common cause of life-threatening infections in newborn babies, and of meningitis in babies up to age 3 months. Most GBS infections can be prevented by giving antibiotics intravenously at the onset of labour to all women who carry GBS. UK guidelines recommend Mums should be offered these antibiotics in labour if GBS has been detected during the current pregnancy, if a previous baby had GBS infection or if she has a fever in labour.
Intravenous antibiotics in labour are highly effective at preventing GBS infection in newborn babies, reducing the risk for a baby born to a woman carrying GBS from around 1 in 300 to less than 1 in 6000. Oral antibiotics should not be given during pregnancy for GBS as they have not been shown to redce GBS infection in babies. There are always small but potentially serious risks associated with taking antibiotics, and this needs to be fully discussed with your midwife or doctor.
Screening for GBS is not routinely offered in the NHS. Laboratory testing for GBS is routinely undertaken at The Doctors Laboratory following the method described in the UK Standard, using enriched culture medium. Two swabs need to be cultured ideally in the last five weeks of pregnancy, to best predict GBS carriage around the time of delivery.