Treatment in labour

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 is 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.)

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, always involves risk. Some women will prefer not to have antibiotics if the risk of their baby developing a GBS infection is only slightly increased, since it may complicate an otherwise natural birth. Antibiotic therapy is also associated with very 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 enable the pregnant woman to make the best decision for herself and her baby.

Antibiotic resistance

Whenever antibiotics are taken, there is always a risk of antibiotic resistance developing. When antibiotics are given to pregnant women, this could affect the mother and her baby.

Data are collected by Public Health England on the susceptibility of group B Streptococci to particular antibiotics. The situation is monitored by the PHE, and reports resistance are included in the data series available here.

GBS is universally sensitive to Penicillin (the drug of choice for intrapartum antibiotic prophylaxis against early-onset GBS infection). There has however been a significant increase in GBS resistance to clindamycin, which was the antibiotic usually offered to women allergic to penicillin. Clindamycin is no longer recommended against GBS as the resistance rate is high – in 2010, 452 GBS isolates were tested and 8% were resistant to Clindamycin. In 2016, 1140 GBS isolates were tested and 26% were resistant to Clindamycin.

For women allergic to penicillin, provided the 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.