II. Epidemiology

  1. Asymptomatic GBS carriers: 15-40% of all pregnancies
  2. Treatment for risk factors prevents 70% Neonatal GBS

III. Indications: Screening for GBS Culture

  1. All pregnant women should be cultured at 35-37 weeks
    1. Current CDC guidelines recommend universal screening
    2. (1996) MMWR Morb Mortal Wkly Rep 45:1-24 [PubMed]
  2. Preterm Labor
  3. Preterm Rupture of Membranes
  4. Pregnant women undergoing surgery of Cervix

IV. Indications: Intrapartum GBS Prophylaxis

  1. Known maternal GBS colonization
  2. Preterm Labor
  3. Preterm Premature Rupture of Membranes
  4. Prolonged Rupture of Membranes exceeding 18 hours
    1. Consider starting antibiotics at 12 hours after ROM
    2. Allows for 2 doses of antibiotics prior to delivery
  5. Prior infant with Group B Streptococcal Sepsis
  6. Multiple Gestation
  7. Maternal intrapartum Fever (over 100.4 F or 38 C)
  8. Intrapartum GBS nucleic acid amplification test positive

V. Labs: GBS Culture

  1. Obtain GBS Culture for indications above
  2. Start GBS Prophylaxis (after GBS Culture) for labor and unknown status (e.g. Preterm Labor, missed universal screening)
  3. GBS Culture need not be repeated if last culture was within last 5 weeks
  4. GBS Prophylaxis may be discontinued if GBS Culture result is found to be negative during treatment

VI. Management: Antibiotics in peripartum until delivery

  1. See Indications above
  2. First line agents
    1. Penicillin G 5 MU IV, then 2.5 MU IV every 4 hours
      1. Preferred first line agent
    2. Ampicillin 2 grams IV, then 1 gram every 4 hours
      1. Penicillin G is preferred
  3. Penicillin Allergy (not Anaphylaxis, Angioedema or Urticaria)
    1. Cefazolin 2 grams IV, then 1 gram every 8 hours
  4. Penicillin Anaphylaxis (or Angioedema, Urticaria)
    1. Growing resistance to Clindamycin and Erythromycin
      1. Manning (2003) Obstet Gynecol 101:74-9 [PubMed]
    2. Agents
      1. Clindamycin 900 mg IV every 8 hours
        1. Do not use unless Clindamycin susceptibility has been tested
      2. Vancomycin 1g IV every 12 hours
        1. Indicated if GBS Antibiotic Resistance suspected

VII. Management: Infant born to mother with known GBS

  1. Path 1: Full Neonatal Sepsis evaluation indications
    1. Signs of Sepsis in the newborn
    2. Mother treated for suspected Chorioamnionitis
  2. Path 2: Limited Sepsis evaluation
    1. Indications
      1. Antibiotic duration <4 hours before delivery
      2. Gestational age <37 weeks
      3. Prolonged Rupture of Membranes >18 hours
    2. Protocol
      1. Observe infant for 48 hours
      2. Evaluate per Neonatal Sepsis protocol
        1. Complete Blood Count
        2. Blood Culture
    3. Antibiotic indications
      1. White Blood Cell Count >30k or <5k
      2. Temperature instability
        1. Newborn Temperature < 97 F (36 C)
        2. Newborn Temperature > 99.6 F (37 C)
      3. Other clinical criteria suggestive of infection
  3. Path 3: Observation
    1. Indications
      1. Antibiotic duration 4 or more hours before delivery
      2. Term, healthy appearing newborn
    2. Protocol
      1. No additional management unless dictated by exam
      2. Observe for 48 hours prior to discharge

VIII. Precautions: Special concerns

  1. Intrauterine monitoring is not contraindicated
    1. FSE and IUPC does not increase neonatal GBS risk
  2. GBS colonization must be reassessed in each pregnancy
    1. Use current GBS status to guide chemoprophylaxis
    2. Prophylaxis not mandated by prior GBS colonization
      1. Only indicated if current pregnancy GBS positive

IX. References

  1. Apgar (2003) AAFP Board Review, Seattle
  2. Morrison (2000) ALSO, p. 14-5
  3. Apgar (2005) Am Fam Physician 71:903-10 [PubMed]
  4. Cagno (2012) Am Fam Physician 86(1): 59-65 [PubMed]

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