Screening & Prevalence
All pregnant patients should be screened for GBS at this gestational age range.
36 0/7 to 37 6/7 weeks
What is the dose of ampicillin for GBS prophylaxis
PCN
Ampicillin
Cefazolin
Clindamycin
Vancomycin
What type of bacteria is GBS
Streptococcus agalactiae
Gram positive cocci in chains
Optimal duration of antibiotics before delivery for maximal neonatal protection
≥4 hours
GBS positive patient receiving ampicillin GBS ppx meets criteria for IAI. What are the next steps
Increase ampicillin dose (1 g q4h > 2 g q6h) and add gent
How long a GBS screen is considered valid
~5 weeks (through 41 weeks gestation)
What is the dose of ampicillin for GBS prophylaxis?
Loading: 2 g IV
Then: 1 g IV q4 hours until delivery
In the absence of intrapartum antibiotic prophylaxis, what percent of those newborns will develop GBS early onset disease
1–2%
Which finding in pregnancy eliminates the need for repeat GBS screening later
GBS bacteriuria in any trimester
Freebie, you're doing great
<3
When do you screen for GBS in a patient with a history of an infant with invasive GBS disease
Patients with this history require GBS ppx in labor regardless of GBS status
Minimum duration of GBS ppx abx exposire that still provides some benefit
≥2 hours
What are the main clinical presentations of GBS early onset disease
Sepsis, pneumonia, or less frequently meningitis
<7 days. Most likely to manifest within the first 12–48 hours after birth
Vertical transmission
This duration of membrane rupture at term warrants prophylaxis if GBS unknown
≥18 hours
What is the recommendation for term GBS+ patients requesting a membrane sweep
Although current evidence is limited, membrane sweeping does not appear to be associated with adverse outcomes in women colonized with GBS.
What is the prevalence of vaginal or rectal GBS colonization in pregnant women
10% and 30%
May be higher in black women, or may vary by location
In PCN allergic patients, when should cefazolin be avoided:
Severe PCN delayed reaction hx
-Skin peeling, or blistering rash
-Sores in mouth, eyes, genitals
-Organ involvement (kidney, liver, lungs)
How far after birth can late onset GBS present?
Late onset = >7 days, can present @ 2-3 months
Which patients do NOT need GBS prophylaxis despite a positive screen.
GBS+ patients who undergo a c-section before the onset of labor and with intact membranes
GBS EOD occurs at a very low rate in this situation (approximately 3 per 1,000,000 live births)
What is the management of asymptomatic bacteriuria with GBS (50 CFU/mL) in the first trimester
Does not require immediate tx. Needs intrapartum GBS ppx
(Identification of asymptomatic bacteriuria with GBS during pregnancy at a level less than 105 CFU/mL does not require maternal antibiotic therapy during the antepartum period but is an indication for intrapartum antibiotic prophylaxis at the time of birth)
Implementation of national guidelines for intrapartum antibiotic prophylaxis has resulted in a reduction in the incidence of GBS EOD of more than ______%
80%, from 1.8 newborns per 1,000 live births in the 1990s to 0.23 newborns per 1,000 live births in 2015
What is the vancomycin dosage for intrapartum GBS prophylaxis
Bonus: cefazolin dosage
Should be based on weight and baseline renal function (20 mg/kg intravenously every 8 hours, with a maximum of 2 g per single dose.)
Ancef: 2 g IV loading. Then 1 g IV q8 hours
Treatment of asymptomatic bacteriuria, which is defined as 105 colony forming units (CFU)/mL or more, has been shown to reduce the risks of what 3 outcomes
1. Pyelonephritis
2. Birth weight less than 2,500 grams
3. preterm birth
What are the indications for GBS prophylaxis with GBS status is unknown
(Name 4)
-Preterm
-ROM >18hrs or more
-Intrapartum temp of 100.4 or higher
-Known GBS positive in previous pregnancy
(intrapartum NAAT results positive/ Hx of previous neonate with invasive GBS disease)
What antibiotics should be used in a patient with GBS bacteruria >105cfu/ml with a PCN allergy. Sensitivities show susceptibility to clinda
Nitro,keflex, fosfomycin, ect.
Clindamycin should NOT be used for antepartum treatment of GBS bacteriuria, even in penicillin-allergic patients — it is concentrated poorly in urine, is metabolized hepatically, and is intended for bloodstream/soft tissue infections, not urinary infections