Group B Streptococcus

Question 1

GBS is a common bowel commensal and carried by up to what percentage of women vaginally?

Answer 1

Around 20% - thought of as carriers
Infants may be exposed to maternal GBS during labour and subsequently develop potentially serious infections
About 50% of babies born to women who carry GBS will become carries themselves, but 1% will become ill themselves

Question 2

Is there screening for it in the UK?

Answer 2

No, but it may be found in routine high vagina, swabs or urine culture

Question 3

What risk factors are there for GBS infection?

Answer 3

Prematurity
Prolonged rupture of membranes
Previous sibling GBS infection - largest risk factor, risk x10
Maternal pyrexia e.g secondary to chorioamnionitis

Question 4

In labour women should be given IV antibiotics if…

Answer 4

Positive high vaginal swab at any time in pregnancy
Previous baby infected with GBS
Gestation <37 weeks regardless of their GBS status
Any intrapartum fever, temp >38

Question 5

What is the antibiotic of choice for GBS prophylaxis?

Answer 5

Benzylpenicillin 3G IV loading dose then 1.5g 4 hourly throughout labour
If allergic: clindamycin/vancomycin

Question 6

Is there a need for antibiotics prior to labour?

Answer 6

No

Question 7

Is maternal request an indication for screening?

Answer 7

No