The “UK Standards for Microbiology Investigations: Processing Swabs for Group B Streptococcal Carriage” (SMI B58) endorses and supports the recommendations that only those pregnant women assessed as being at high risk should be tested. The document provides a recommended method for such testing. This does not however prevent tests being carried out where a doctor thinks it is necessary, with the Royal College of Obstetricians and Gynaecologists guidance setting out the criteria for making such judgements.
The Royal College of Obstetricians and Gynaecologists (RCOG) has also carefully considered the potential benefits and harms of screening for GBS carriage during pregnancy and has agreed that there is no clear evidence to show that screening all pregnant women in the UK would be beneficial. There are concerns that, given the relatively low risk associated with most cases of GBS carriage, a positive screen may result in unnecessary and potentially harmful treatment. One of the potential harms of screening for GBS during pregnancy is that large numbers of women might be given antibiotics during labour, risking death or serious injury to a few women from an allergic reaction (anaphylaxis) to the drugs; there is also a real risk that strains of bacteria become resistant to antibiotics.