Questions & Answers About Implementing the 2010 Guidelines for Neonatal Providers

Algorithm for secondary prevention of early-onset group B streptococcal (GBS) disease among newborns

Q: What does the neonatal algorithm address?

A: The neonatal algorithm provides guidance on which newborns require full diagnostic evaluations, limited diagnostic evaluations, antibiotic therapy, and observation for the purpose of secondary prevention of early-onset GBS disease. For newborns requiring observation, it also includes guidance on when infants can be discharged to be observed at home instead of being observed in the hospital. The recommended management depends on whether the newborn shows signs of neonatal sepsis or was exposed to maternal chorioamnionitis, whether the mother had an indication for GBS intrapartum antibiotic prophylaxis and received adequate GBS intrapartum antibiotic prophylaxis, the duration of the mother’s rupture of membranes, and the newborn’s gestational age.

Q: Where can I find the neonatal algorithm for secondary prevention of early-onset GBS disease?

A: An app to guide clinical management of neonates according to the 2010 guidelines can accessed here.

In addition, the algorithm can be found here.

Q: Which infants does the neonatal algorithm apply to?

A: The algorithm applies to all newborns.

Q: What qualifies as adequate GBS intrapartum antibiotic prophylaxis in a woman who either had a positive GBS screening test or unknown GBS status and gestational age <37 weeks, intrapartum temperature ≥ 100.4°F, or rupture of membranes ≥18 hours?

A: The mother should have received ≥4 hours of intravenous penicillin, ampicillin, or cefazolin prior to delivery. If she received penicillin, she should have initially received 5 million units IV then 2.5-3.0 million units IV every 4 hours until delivery. If she received ampicillin, she should have received 2 grams IV in the initial dose followed by 1 gram IV every 4 hours until delivery (with the exception of women with preterm premature rupture of membranes, who may have received 2 grams IV in the initial dose followed by 1 gram IV every 6 hours) For cefazolin, she should have received a first dose of 2 grams IV followed by 1 gram IV every 8 hours until delivery.

Q: Why does a mother with an indication for intrapartum prophylaxis need to have received antibiotics for at least 4 hours to be considered to have received adequate intrapartum prophylaxis?

A: Beta-lactam antibiotics for GBS prophylaxis administered for at least 4 hours before delivery have been found to be highly effective at preventing neonatal surface colonization with GBS as well as invasive early-onset GBS disease. Shorter durations may have some benefit but have not been established as effective in preventing early-onset GBS disease.

Q: Why are penicillin, ampicillin, and cefazolin considered adequate for GBS intrapartum antibiotic prophylaxis while clindamycin and vancomycin are considered inadequate for GBS intrapartum antibiotic prophylaxis?

A: The efficacy of penicillin and ampicillin as intravenously administered intrapartum agents for the prevention of early-onset neonatal GBS disease has been demonstrated in clinical trials and large observational studies. The efficacy of alternatives to penicillin or ampicillin has not been evaluated. However, cefazolin has similar pharmacokinetics and dynamics to penicillin and ampicillin and achieves high intra-amniotic concentrations. In contrast, data on the ability of clindamycin, erythromycin, and vancomycin to reach bactericidal levels in the fetal circulation and amniotic fluid are very limited.

Q: Why do some experts recommend waiting several hours before ordering a complete blood count with differential and platelets in an infant with suspected sepsis?

A: The sensitivity of a complete blood count with differential and platelets is lowest immediately after birth, and its performance as a screen for sepsis can be improved by obtaining the blood specimen between 6 and 12 hours of life.

Q: What do I do if an infant born to a mother with a negative GBS screening test looks ill?

A: If signs of sepsis develop in any infant, regardless of their mother’s GBS status, a full diagnostic evaluation should be done and antibiotic therapy initiated.

Q: Is a lumbar puncture mandatory for infants who are symptomatic?

Q: Is there value in measuring acute phase reactants (e.g., C - reactive protein) in infants with suspected sepsis?

A: Measuring acute phase reactants is not considered part of the full diagnostic evaluation of infants with suspected sepsis. The sensitivity and specificity of these tests are too low in infants for them to be consistently useful in decisions to initiate treatment for suspected sepsis. However, some experts have argued that acute phase reactants may be useful in decisions to stop antibiotic treatment for suspected cases of sepsis.

Q: How soon can antibiotics be discontinued after birth if an infant with suspected sepsis becomes asymptomatic and the mother received intrapartum antibiotics which might limit the accuracy of a blood culture?

A: Clinicians should follow the usual standard of care in making decisions on length of treatment of infants with suspected sepsis. CDC has no recommendations on the length of treatment of infants with suspected sepsis.

Q: Which antibiotics should be used to treat an infant with suspected sepsis whose mother was GBS-negative? What if the mother was GBS-positive or has unknown GBS status?

A: Regardless of the mother’s GBS status, antibiotic therapy for any infant with signs of sepsis should include ampicillin for GBS as well as antibiotics that cover Escherichia coli and other gram-negative pathogens. The choice of antibiotics should take into account local resistance patterns.

Q: Are efforts to prevent early onset GBS disease leading to increased E.coli sepsis among newborns?

A: Decreases in the incidence of early-onset GBS sepsis have not been accompanied by increases in incidence of early-onset sepsis caused by other pathogens. Most studies, including population-based multicenter studies, have found stable or decreasing rates of non-GBS early-onset sepsis during a period of increasing use of intrapartum antibiotic prophylaxis for GBS. Increases in invasive E. coli infections have been reported among preterm and low-birth-weight or very low-birth-weight infants, but the trends have not been consistent over time or across studies. For example, a multicenter study of sepsis in preterm infants that reported an increase in E. coli incidence during 1991-1993 and 1998-2000 found stable rates of E. coli sepsis during 2002-2003.

Q: Is the decreased rate of early-onset GBS disease since the early 1990s representative of a true decline in the neonatal GBS disease burden, or does it just reflect a decreased yield of blood cultures in the setting of intrapartum antibiotics?

A: Nationally representative hospital discharge diagnostic code data demonstrated a steady decrease in clinical sepsis rates during 1990-2002, with a marked decline in clinical sepsis among term infants following the issuance of the 1996 GBS prevention guidelines; these data suggest that the observed decline in early-onset GBS disease is a result of prevented cases of illness and not simply of sterilization of neonatal blood cultures as a result of exposure to maternal antibiotics.

Q: Has use of intrapartum antibiotic prophylaxis changed the clinical picture of early-onset GBS disease?

A: Several studies conducted since 1996 have found no significant difference in the clinical presentation of early-onset GBS disease between infants exposed to intrapartum antibiotics and those not exposed. Approximately 90% of cases of early-onset GBS disease continue to manifest within the first 24 hours of life.

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