Group B Strep in Pregnancy

(GBS status, GBS)

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Definition

-  Infection/isolation of Group B Strep (GBS) in pregnant mother &/or neonate

 

Features

-  Caused by Group B Strep (GBS)

-  Found in 20-40% women, normal GIT or urogenital tract flora

-  15-25% asymptomatic carriers

-  0.5-1% GBS+ mothers develop S/S

-  Most common cause of life-threatening infection in newborns

-  Morbidity ass w anaphylaxis to penicillin offset by reduction in incidence of neonatal & maternal sepsis

-  Materno-foetal transmission via anatomical ascent or during delivery

-  Risk Factors for infants developing early onset GBS infection

-  Gestation <37 weeks

-  ROM >18 hrs

-  Maternal fever >38oC

-  Previous GBS infected baby

-  GBS bacteruria during pregnancy

 

Associated S/S

-  Maternal

-  Cystitis (UTI)

-  Chorioamnionitis

-  Endometritis (PID)

-  Stillbirth

-  Endocarditis

-  Meningitis

-  UTI

-  Pelvic abscess

-  Foetal

-  Early onset (<7 days, avg 12hrs)

-   Nonfocal sepsis

-   Pneumonia

-   Meningitis

-  Late onset (>7 days, avg 36 days)

-   Nonfocal bacteraemia

-   Meningitis

 

Ix

-  Recommended antenatal screen between 35-37 weeks gestation

-  Low vaginal swab (LVS) +/- anorectal swab (patient can collect)

-  NOT routine at all centres

 

Mx

-  Penicillin chemoprophylaxis

-  Benzylpenicillin 1.2g (or 3g) IV loading dose

-  THEN 600mg (or 1.2g) IV 4/24 until delivery

-  If Penicillin allergy

-  Sensitivity: Cephazolin 2g IV loading dose

-   THEN 1g IV 8/24 until delivery

-  Anaphyalaxis

-   Erythromycin 500mg IV 6/24 until delivery

-   OR Clindamycin 600mg IV 8/24 until delivery

-  Indicated intrapartum (at onset of established labour) if

-   Previous GBS infected baby

-   GBS bacteruria during pregnancy

-   GBS positive or unkown &

-   Labour <37 weeks gestation

-   Ruptured membranes >18hrs

-   Febrile mother >38oc in labour

-   GBS bacteruria

-   Previous baby w GBS neonatal disease

-  Elective LUSCS: chemoprophylaxis not recommended

-  Unless ruptured membranes >18hrs

-  Babies born to GBS+ mothers closely monitored for S/S

-  If no Abx in labour OR Abx given <4hrs prior to delivery OR <35weeks gestation & develop S/S sepsis

-  FBE, CRP, BC

-  BenPen + Gentamicin

-  Observe 48hrs

 

 

 

References

 

RANZCOG – College Statement on GBS 2009

eMedicine – 235054

Peninsula Health CPG: Group B Streptococcus, June 2011