II. Epidemiology
- Asymptomatic GBS carriers: 15-40% of all pregnancies
- Treatment for risk factors prevents 70% Neonatal GBS
III. Indications: Screening for GBS Culture
- All pregnant women should be cultured at 35-37 weeks
- Current CDC guidelines recommend universal screening
- (1996) MMWR Morb Mortal Wkly Rep 45:1-24 [PubMed]
- Preterm Labor
- Preterm Rupture of Membranes
- Pregnant women undergoing surgery of Cervix
IV. Indications: Intrapartum GBS Prophylaxis
- Known maternal GBS colonization
- Preterm Labor
- Preterm Premature Rupture of Membranes
- Prolonged Rupture of Membranes exceeding 18 hours
- Consider starting Antibiotics at 12 hours after ROM
- Allows for 2 doses of Antibiotics prior to delivery
- Prior infant with Group B Streptococcal Sepsis
- Multiple Gestation
- Maternal Intrapartum Fever (over 100.4 F or 38 C)
- Intrapartum GBS Nucleic Acid amplification test positive
V. Labs: GBS Culture
- Obtain GBS Culture for indications above
- Start GBS Prophylaxis (after GBS Culture) for labor and unknown status (e.g. Preterm Labor, missed universal screening)
- GBS Culture need not be repeated if last culture was within last 5 weeks
- GBS Prophylaxis may be discontinued if GBS Culture result is found to be negative during treatment
VI. Management: Antibiotics in peripartum until delivery
- See Indications above
- First line agents
- Penicillin G 5 MU IV, then 2.5 MU IV every 4 hours
- Preferred first line agent
- Ampicillin 2 grams IV, then 1 gram every 4 hours
- Penicillin G is preferred
- Penicillin G 5 MU IV, then 2.5 MU IV every 4 hours
-
Penicillin Allergy (not Anaphylaxis, Angioedema or Urticaria)
- Cefazolin 2 grams IV, then 1 gram every 8 hours
- Penicillin Anaphylaxis (or Angioedema, Urticaria)
- Growing resistance to Clindamycin and Erythromycin
- Agents
- Clindamycin 900 mg IV every 8 hours
- Do not use unless Clindamycin susceptibility has been tested
- Vancomycin 1g IV every 12 hours
- Indicated if GBS Antibiotic Resistance suspected
- Clindamycin 900 mg IV every 8 hours
VII. Management: Infant born to mother with known GBS
- Path 1: Full Neonatal Sepsis evaluation indications
- Signs of Sepsis in the newborn
- Mother treated for suspected Chorioamnionitis
- Path 2: Limited Sepsis evaluation
- Indications
- Antibiotic duration <4 hours before delivery
- Gestational age <37 weeks
- Prolonged Rupture of Membranes >18 hours
- Protocol
- Observe infant for 48 hours
- Evaluate per Neonatal Sepsis protocol
- Antibiotic indications
- White Blood Cell Count >30k or <5k
- Temperature instability
- Newborn Temperature < 97 F (36 C)
- Newborn Temperature > 99.6 F (37 C)
- Other clinical criteria suggestive of infection
- Indications
- Path 3: Observation
- Indications
- Antibiotic duration 4 or more hours before delivery
- Term, healthy appearing newborn
- Protocol
- No additional management unless dictated by exam
- Observe for 48 hours prior to discharge
- Indications
VIII. Precautions: Special concerns
- Intrauterine monitoring is not contraindicated
- FSE and IUPC does not increase neonatal GBS risk
- GBS colonization must be reassessed in each pregnancy
- Use current GBS status to guide chemoprophylaxis
- Prophylaxis not mandated by prior GBS colonization
- Only indicated if current pregnancy GBS positive
IX. References
- Apgar (2003) AAFP Board Review, Seattle
- Morrison (2000) ALSO, p. 14-5
- Apgar (2005) Am Fam Physician 71:903-10 [PubMed]
- Cagno (2012) Am Fam Physician 86(1): 59-65 [PubMed]