GBS is a common bacterium carried by roughly 1 in 4 people. The NHS does not routinely screen for it but offers antibiotics during labour if risk factors are present. Private testing is available between 35 and 37 weeks for around 35 to 40 pounds. With antibiotics, the risk of GBS infection in newborns drops significantly.
GBS is a type of bacteria (Streptococcus agalactiae) that naturally comes and goes in the body. Carrying GBS does not mean you are unwell or that anything is wrong. It is not a sexually transmitted infection. GBS can be present in the vagina, rectum, or urinary tract, and it can come and go throughout pregnancy.
If GBS is present in the vagina when your waters break or during delivery, there is a small chance it can be passed to the baby. In approximately 1 in 1,750 newborns in the UK, GBS causes early-onset infection within the first 7 days of life. This can include sepsis, pneumonia, or meningitis. With appropriate antibiotics during labour, the risk drops significantly.
The NHS in England does not currently offer routine GBS screening. The UK National Screening Committee has reviewed the evidence and concluded that universal screening has not been shown to reduce the overall rate of GBS disease compared with the current risk-based approach.
Instead, antibiotics during labour are offered if GBS has been detected incidentally during pregnancy, if you have had a previous baby affected by GBS infection, if your waters break before 37 weeks, if you have a temperature during labour, or if your waters break more than 18 to 24 hours before delivery.
You can arrange a private ECM swab test through the Group B Strep Support charity or private clinics for around 35 to 40 pounds. It involves a self-taken vaginal and rectal swab sent to a lab by post. The test is most informative between 35 and 37 weeks.
If you test positive privately, share the result with your midwife. Most NHS trusts will offer IV antibiotics during labour if you have a documented positive GBS result.
Antibiotics are given through a drip during labour, not during pregnancy. Penicillin is most commonly used. For the antibiotics to be most effective, the first dose should ideally be given at least 4 hours before delivery.
If you received antibiotics for GBS, your baby will be observed for at least 12 hours. The team will watch for signs of infection such as difficulty breathing, poor feeding, unusual sleepiness, or abnormal temperature.
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