The Prevention of Early-onset Neonatal Group B Streptococcal Disease
The purpose of this guideline is to provide guidance for obstetricians, midwives and neonatologists on the prevention of early-onset neonatal group B streptococcal (EOGBS) disease. Prevention of late-onset GBS and treatment of established GBS disease is not considered beyond initial antibiotic therapy.
Group B streptococcus (Streptococcus agalactiae) is recognised as the most frequent cause of severe earlyonset (at less than 7 days of age) infection in newborn infants. However, there is still controversy about its prevention. Surveys in 2001 and 2008 demonstrated that less than 1% of UK maternity units were performing systematic screening for GBS and, to date, UK clinicians have not generally adopted the US and Canadian practice of routine screening for GBS carriage. Extrapolation of practice from the USA to the UK may, however, be inappropriate. The incidence of EOGBS disease in the UK in the absence of systematic screening or widespread intrapartum antibiotic prophylaxis (IAP) is 0.5/1000 births, which is similar to that seen in the USA after universal screening and IAP, despite comparable vaginal carriage rates. The incidence of cultureconfirmed early-onset disease in the USA has fallen in association with the introduction of screening pregnant women for GBS.3 The current US guidelines advise that all women colonised with GBS at 35–37 weeks of gestation (or labouring before this time) should be offered IAP, usually in the form of high-dose intravenous benzylpenicillin or ampicillin. IAP has been shown to significantly reduce the risk of culture-positive earlyonset but not late-onset disease (occurring 7 or more days after birth). There is also indirect evidence of an impact on neonatal deaths. A review of sepsis-related neonatal mortality in the USA showed a decline in mortality in the first week after birth, coinciding with the introduction of IAP. However, a Cochrane review concluded that, while IAP for colonised mothers reduced the incidence of EOGBS disease, it has not been shown to reduce all causes of mortality or GBS-related mortality. There have been no studies addressing whether routine screening has had any impact on all-cause mortality. Antenatal screening and treatment may carry disadvantages for the mother and baby. These include anaphylaxis, increased medicalisation of labour and the neonatal period, and possible infection with antibiotic-resistant organisms, particularly when broadspectrum antibiotics such as amoxicillin are used for prophylaxis. The UK National Screening Committee examined the issue of strategies for the prevention of EOGBS disease in November 2008 and recommended that routine screening using bacteriological culture or near-patient testing techniques should not be introduced into UK practice.
The full guideline can be downloaded as pdf using the link below.
RCOG Audit on the prevention of neonatal Group B Streptoccocal disease
A report of this audit can be downloaded here.