With disease as serious as group B Strep infection, prevention is much better than treatment.
The best prevention (or prophylactic treatment) for GBS infection developing in newborn babies is giving intravenous antibiotics (to the mother) during labour. When given from the start of labour or waters breaking (and ideally 4 hours before delivery), this has proven to be very effective at preventing GBS infection in the baby. Sadly, waiting to give antibiotics to the baby after delivery will sometimes be too late.
Giving intravenous antibiotics in labour to women known to carry group B Strep could reduce GBS infection in their newborn babies by over 80%.
(These recommendations will need periodic reappraisal to incorporate advances in technology, new research or other refinements but are we believe the most appropriate for the UK in the light of all data available at present.)
Screening for GBS is not recommended by the UK National Screening Committee nor the Royal College of Obstetricians & Gynaecologists. Current prevention centres around using a ‘risk factor’ approach to determine which women should be offered intravenous antibiotics in labour. Risk factors that trigger the offer of these antibiotics include GBS detected this pregnancy from maternal swabs or urine, Mum having a high temperature during labour, having previously had a baby infected with GBS, and Mum going into preterm labour. However, 60% of newborn babies who develop GBS infection are born to mothers without no known risk factors (apart from unknowingly carrying GBS).
Until sensitive ECM testing for GBS carriage is available to all pregnant women (click here for more information on ECM testing), our medical advisory panel has made the following recommendations for a risk based strategy (for the risk factors, click here):
1. Which newborn babies are at raised risk of group B Strep infection?
Women at higher risk should be strongly advised to have intravenous antibiotics immediately at onset of labour until delivery. At higher risk means:
- Women who carry GBS AND have another risk factor
- Women who may/may not carry GBS, but have multiple risk factors
- Women who have had a previous baby infected with GBS
- Women who have had GBS detected in their urine during the current pregnancy
- Women with a fever during labour
Women at increased risk should be offered intravenous antibiotics immediately at onset of labour through to delivery. At increased risk means:
- Women who are known to carry GBS with no other risk factors
- Women who carried GBS in a previous pregnancy (who should be offered the option of either the antibiotics in labour or a specific ECM test for GBS with the offer of antibiotics if the result is positive
- Women whose GBS status is unknown and who have ONE risk factor not mentioned above
2. What antibiotics should be offered in labour?
Intravenous antibiotics against GBS infection in the baby should be given to the mother at least 4 hours before delivery if possible (if only 2 hours before delivery is possible, this may be sufficient and should give considerable reassurance).
Intravenous antibiotics recommended for women in labour are:
- Penicillin G: given as 3g (or 5MU) intravenously at first and then 1.5g (or 2.5MU) at 4-hourly intervals until delivery.
- For women allergic to penicillin: provided a woman has not had severe allergy to penicillin, a cephalosporin should be used. If there is any evidence of severe allergy to penicillin, vancomycin should be used.
For women allergic to penicillin, Clindamycin is no longer recommended as the current resistance rate in the UK is high.
Where infection of the membranes is diagnosed or suspected or where there is preterm prolonged rupture of membranes, broad spectrum intravenous antibiotics should be given which include adequate GBS cover.
If a woman is allergic to Penicillin or any other antibiotic, she MUST tell her healthcare professionals.
The use of any drug, including antibiotics, is not without risk. Some women will prefer not to have antibiotics if their risk is only slightly increased, since it may complicate an otherwise natural birth. Antibiotic therapy is also associated with rare, but significant complications. The risk of a GBS infection in the baby must be balanced against the wishes and beliefs of the woman in labour and against her risk of an adverse reaction to the antibiotics. The antibiotic options should be discussed with the healthcare professional to make the best decision for the pregnant woman and her baby.
3. What should happen after birth?
With any policy that involves treating certain women with penicillin to prevent GBS infection following rupture of membranes or the start of labour, a strategy for the management of the newborn baby is required. Our medical advisory panel has put together a simple chart showing the recommended treatment for newborn babies with regard to GBS. Click here to view it.
Babies born at increased/high risk to Mums who HAVE received antibiotics for more than 2 hours before delivery should be:
- carefully assessed by an appropriately trained Paediatrician or Advanced Neonatal Nurse Practitioner
- If completely healthy, no antibiotics for the baby are required
- A period of monitoring (12-24 hours) may be appropriate for those at highest risk of infection.
Babies born at increased/high risk to Mums who HAVE NOT received antibiotics for more than 2 hours before delivery should be:
- Examined thoroughly and investigated by a Paediatrician as appropriate.
- Observed for a minimum of 12 hours, ideally 24 hours.
- If completely healthy, no antibiotics for the baby are required.
For well babies at highest risk of infection, monitoring (12-24 hours) may be appropriate and this should be undertaken as a minimum if the baby is not screened and treated for infection.
If there is any doubt about whether an infection is present, the baby should be started on intravenous antibiotics until it is known that s/he is not infected.