Intrapartum Antimicrobial Prophylaxis of Group B Streptococcus (GBS)
- At 36 0/7 to 37 6/7 weeks of gestation, obtain single swab from lower vagina and anorectum (Indicate on requisition if patient ß-lactam allergic as lab will perform susceptibility testing for clindamycin and vancomycin)
- Give intrapartum prophylactic antibiotics upon commencement of labour if:
- culture positive for GBS or
- GBS bacteriuria during present pregnancy or
- previous baby with invasive GBS disease or
- unknown GBS status and patient has one or more of the following risk factors:
- pre-term labour (< 37 weeks gestation)
- prolonged rupture of membranes ( ≥ 18h) and/or labour expected to last ≥ 18h at term (≥ 37 weeks)
- maternal fever (≥ 38ºC)
| Antimicrobial Regimen | Dose & Duration |
|---|---|
| - Ampicillin + gentamicin recommended if chorioamnionitis suspected. | |
| Penicillin | 5MU IV given ideally at least 4h prior to delivery then |
| 2.5-3MU IV q4h until delivery or labour stops | |
Alternative | |
| Ampicillin | 2g IV given ideally at least 4h prior to delivery then |
| 1g IV q4h until delivery or labour stops | |
Low risk ß-lactam allergy
| Antimicrobial Regimen | Dose & Duration |
|---|---|
| Cefazolin | 2g IV given ideally at least 4h prior to delivery then |
| 1g IV q8h until delivery or labour stops |
High risk ß-lactam allergy/anaphylaxis
| Antimicrobial Regimen | Dose & Duration |
|---|---|
| Clindamycin | 900mg IV q8h until delivery or labour stops |
Alternative if clindamycin resistance or unknown susceptibility to clindamycin | |
| Vancomycin | 20mg/kg (max 2g) IV q8h until delivery or labour stops |