PEDIATRICS Vol. 99 No. 3 March 1997, pp. 489-496

AMERICAN ACADEMY OF PEDIATRICS:
Revised Guidelines for Prevention of Early-onset Group B Streptococcal (GBS) Infection

Committee on Infectious Diseases and Committee on Fetus and Newborn

	ABSTRACT

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In 1992, the Committee on Infectious Diseases and Committee on Fetus and Newborn of the American Academy of Pediatrics provided guidelines for prevention of early-onset group B streptococcal (GBS) disease through intrapartum chemoprophylaxis of selected maternal GBS carriers.¹ The guidelines were based on demonstrated efficacy in randomized, controlled clinical trials and selected only women with GBS colonization who had an obstetric risk factor.² The guidelines were controversial^3,4 and their implementation incomplete.⁵ Since 1992, additional data have become available, and experience with the guidelines has been gained in numerous medical centers. Recently, consensus guidelines were developed by obstetricians, pediatricians, family practitioners, and public health authorities and published by the Centers for Disease Control and Prevention.⁶ These recommendations are supported by the American College of Obstetricians and Gynecologists⁷ and the American Academy of Pediatrics. This statement reviews the selection of pregnant women for chemoprophylaxis and provides an algorithm for management of their newborns.

	RATIONALE FOR THE REASSESSMENT OF THE INITIAL AAP GUIDELINES

The 1992 guidelines of the American Academy of Pediatrics (AAP) were based on controlled clinical trials demonstrating the efficacy of intrapartum chemoprophylaxis in group B streptococcal (GBS) carriers (identified by anogenital cultures at 26 to 28 weeks of gestation) who had one or more of the following risk factors: (1) preterm labor at <37 weeks of gestation, (2) premature rupture of membranes at <37 weeks of gestation, (3) fever during labor, (4) rupture of membranes 18 hours before delivery, and (5) previous delivery of a sibling with invasive GBS disease. Several problems, however, limited implementation of the guidelines. Obstetric caregivers expressed the following concerns: (1) cultures at 26 to 28 weeks of gestation may not predict GBS colonization status at delivery, (2) making prenatal GBS culture results available to the delivery hospital might be difficult, (3) positive cultures may result in inappropriate use of antenatal oral antibiotics, (4) culture-based GBS screening to identify candidates for intrapartum chemoprophylaxis would be costly, and (5) antibiotic-resistant bacteria may emerge.³ The American College of Obstetricians and Gynecologists (ACOG) favored a pragmatic strategy in which all women with risk factors would be given intrapartum chemoprophylaxis without culture-based screening.⁴ The risk factors identified were the same as those listed in the AAP document. According to estimates, the proposed ACOG strategy would prevent a similar number of cases of neonatal GBS sepsis as would the culture screening and risk factor-based selective strategy in the original AAP guidelines. However, the number of women receiving intrapartum chemoprophylaxis would increase from ~5% to 20%.^6,8,9

Pediatricians also had reservations about the 1992 AAP guidelines, especially given the scarcity of information to guide their management of asymptomatic newborns born to women given intrapartum chemoprophylaxis. Many considered performance of laboratory evaluations and initiation of antimicrobial therapy to be obligatory, resulting in prolonged hospital stays and considerable expense. Finally, it was questioned whether alternative approaches would prevent cases of early-onset GBS disease in term infants whose mothers had GBS colonization but no recognizable obstetric risk factors, an estimated 25% to 30% of all cases of early-onset GBS disease.^2,9

These issues led to the revision of the guidelines, which include several major changes: (1) a choice of two strategies, one based on screening cultures and risk factors, the other on identifiable risk factors without screening cultures; (2) culture screening at 35 to 37 weeks of gestation; (3) a prevention strategy for GBS carriers at term without risk factors; (4) the use of penicillin G as the preferred prophylactic agent; and (5) an algorithm for the management of infants whose mothers receive prophylaxis. The following summary of the salient components of the new prevention guidelines is intended to enhance interpretation and implementation.

	EPIDEMIOLOGY OF EARLY-ONSET GBS DISEASE AND THE BENEFITS OF CHEMOPROPHYLAXIS

Group B streptococcus (Streptococcus agalactiae) has been recognized as a significant cause of perinatal morbidity and mortality for >2 decades. In pregnant women, it causes asymptomatic bacteriuria, urinary tract infection, and amnionitis, and in women recently delivered, it causes endometritis and wound infection.² On the basis of age- and race-adjusted projections for the entire US population in 1990, 7600 cases of infant GBS sepsis (1.8/1000 live births) were estimated to occur, resulting in 310 deaths.⁶ Morbidity attributable to overwhelming septicemia and neurologic sequelae of meningitis is substantial, but has not been estimated recently. Invasive disease with onset during the first week of life (early-onset disease) constitutes ~80% of GBS cases, results from transmission of group B streptococcus during labor or delivery from mother to infant (ie, vertical transmission), and is characterized by septicemia, pneumonia, or meningitis.

Several obstetric factors are associated with increased risk for early-onset GBS disease, including giving birth before 37 weeks of gestation, rupture of membranes 18 hours before delivery, and intrapartum fever.^2,8,9 The incidence of GBS disease also is higher in neonates born to women with heavy GBS colonization, of African-American descent, <20 years of age, and who have ruptured membranes before onset of labor, GBS bacteriuria during pregnancy, or low concentrations of anti-GBS capsular antibody in their sera.^2,6,8 Because nearly 90% of neonates with early-onset sepsis have onset of signs of infection within 12 hours of birth,⁸ the most effective strategy available for prevention of GBS disease is chemoprophylaxis of women during labor.

Several randomized, controlled clinical trials of intrapartum chemoprophylaxis have demonstrated a significant reduction in vertical transmission of group B streptococcus and early-onset neonatal sepsis.^6,9,10 Some trials also have reported an associated decrease in maternal febrile morbidity.⁹ The design and prophylactic agent (ampicillin or penicillin) in these trials varied, but all used maternal GBS cultures to select candidates for prophylaxis.^2,6 A recent meta-analysis estimated that a 30-fold reduction in early-onset disease would result from intrapartum chemoprophylaxis¹⁰ for all pregnant women with GBS colonization (ie, carriers) with or without obstetric risk factors. Both approaches (GBS culture-based and risk factors without culture) were cost-beneficial^11,12 and comparable to maternal screening and intervention programs for other perinatal diseases (such as syphilis).⁶

	IDENTIFICATION OF GBS CARRIERS

GBS colonization in women varies among ethnic and age groups, but rates are similar in pregnant and nonpregnant women. In most studies, between 15% and 30% of women are GBS vaginal or anorectal carriers.^2,13-15 The rate of GBS isolation from pregnant women depends on the body site sampled and the specific media used to process cultures. Collection of specimens from two sites, the lower vagina and rectum, increases the likelihood of GBS isolation by 5% to 27% when compared with sampling of only the lower vagina.^13-15 Collection of cervical specimens rather than lower vaginal specimens decreases the yield of group B streptococcus. The use of broth (not solid) media that contain antimicrobial agents (selective broth) to inhibit competing organisms is essential, because these media increase the yield of group B streptococci from cultures by 50%.^16,17 Two selective broth media, SBM (Becton-Dickinson Microbiology Systems, Cockeysville, MD) and Lim broth (Becton-Dickinson), are commercially available. Culture swabs may be placed in a transport medium (such as Amies' medium, Difco, West Molesey, Surrey, UK) at environmental temperature for up to 96 hours, permitting shipment from clinics to microbiology laboratories.

GBS colonization rates do not change with trimester of pregnancy, but the duration of carriage in individuals is unpredictable. Early to midgestation screening cultures do not correctly identify all women who are positive for group B streptococcus at delivery. The later in pregnancy that cultures are performed, the better the correlation with culture results at delivery.^6,14 One study estimated that a single positive GBS culture at 26 to 28 weeks of gestation predicted carriage at delivery, with a sensitivity of 70% and a specificity of 90%.¹⁴ Among 26 women whose prenatal cultures were obtained within 5 weeks of delivery, concordance with intrapartum culture results was 100% (ie, no false-negative or false-positive results were obtained).¹⁴

	SELECTION CRITERIA FOR CANDIDATES TO RECEIVE INTRAPARTUM CHEMOPROPHYLAXIS: THREE APPROACHES

Three general methods have been advocated to select women for intrapartum chemoprophylaxis: (1) all GBS carriers are identified by prenatal culture and given intrapartum prophylaxis; (2) only those GBS carriers with an identifiable risk factor are treated; or (3) all women with an obstetric factor associated with increased risk for neonatal GBS septicemia (without prenatal cultures) receive intrapartum prophylaxis. In Australia, Garland and Fliegner¹⁸ evaluated the first approach and gave intrapartum penicillin G prophylaxis to all GBS carriers identified at 32 weeks of gestation. Their study was not randomized, but the incidence of early-onset GBS disease among the >30 197 women in the prenatal culture-screened population was significantly lower (P = .04) than in the 26 915 women who had no screening.¹⁸ One rationale for considering prophylaxis for all GBS carriers is that this method could potentially reduce the 25% to 30% of cases of early-onset GBS disease not associated with the maternal risk factors,^2,9 as identified in the original recommendations from the AAP¹ and ACOG.⁴ Also, many obstetric patients want their GBS culture status to be determined so that they may decide whether they want to receive intrapartum chemoprophylaxis.^3,6 However, providing all GBS carriers with intrapartum chemoprophylaxis would result in treating ~25% of obstetric patients.^9,12-15

The second approach, that of the 1992 AAP guidelines, was based on clinical trials documenting the efficacy of a screening culture-based plus risk factor method^9,19,20 and the desire to limit the number of pregnant women who received prophylaxis to ~5%.⁹ This method was estimated to prevent ~70% to 75% of early-onset GBS cases.

The third approach, favored by ACOG, was risk factor-based without screening cultures.⁴ This method eliminated problems associated with determination of prenatal GBS culture status and would prevent a similar number of cases of invasive GBS infection as the culture plus risk factor-based method. However, the number of women who would receive prophylaxis would increase to ~20%.^6,9 The first and third approaches target ~20% to 25% of pregnant women to prevent ~70% of infant cases.^1,6,9 A culture-based method that provides chemoprophylaxis to GBS carriers without risk factors would theoretically prevent more infant cases (~90%).

When these different approaches are being evaluated, it is important to consider two caveats. Clinical trials directly comparing the efficacy and cost of the three strategies are not available. Maternal intrapartum chemoprophylaxis will not prevent all cases of early-onset GBS disease, and the impact, if any, on late-onset infection is unknown.

	ADVERSE EFFECTS OF INTRAPARTUM CHEMOPROPHYLAXIS

Three concerns underlie the need to limit the target population for intrapartum chemoprophylaxis: (1) the potential for serious adverse reactions to penicillin, (2) the possible emergence of antibiotic-resistant bacteria, and (3) cost. The rate of fatal anaphylaxis to penicillin in the general population has been estimated at 1 in 100 000, and less severe reactions would be expected in another .7% to 10%.²¹ These estimated rates should be lower in young, healthy pregnant women in a hospital setting, but adverse effects should be considered when estimating benefit versus risk.

Widespread antimicrobial use is known to increase the risk for emergence of antimicrobial-resistant organisms, although to date, GBS resistance has not been reported. Two or three doses of maternal penicillin G are unlikely to result in GBS resistance. Some concern exists that other pathogens, especially gram-negative enteric organisms, could become more prevalent with widespread intrapartum antimicrobial use.²² Surveillance is indicated to determine the potential for these phenomena.

Amstey and Gibbs²³ proposed that penicillin G is preferable to ampicillin for intrapartum chemoprophylaxis. Both drugs have similar in vitro activity against group B streptococci, and both achieve bactericidal concentrations in amniotic fluid and fetal tissues. Ampicillin, however, has a much broader spectrum of activity than penicillin G and is theoretically more likely to lead to selection of resistant organisms than is penicillin. The recommended alternative agents for women with a history of penicillin allergy (clindamycin and erythromycin) are active in vitro against group B streptococci, but these drugs have not been evaluated for efficacy in prevention of early-onset GBS disease.

	INTRAPARTUM CHEMOPROPHYLAXIS: CONSENSUS GUIDELINES

The new recommendations for intrapartum chemoprophylaxis to prevent early-onset GBS neonatal disease represent a consensus of experts and are supported by the ACOG and the AAP. More detailed information regarding aspects of the management of pregnant women is given in the Centers for Disease Control and Prevention (CDC)⁶ and ACOG⁷ publications. The recommended approaches expand the potential number of cases of early-onset GBS disease that will be prevented by combining previous strategies and considering variations in obstetric populations. The success of intrapartum chemoprophylaxis depends on selection of appropriate candidates and prompt administration of intravenous penicillin G¹⁹ after hospital admission for delivery.²⁴ These new approaches and their rationale are briefly summarized.

	CULTURE AND RISK FACTOR-BASED APPROACH

A combination of the features of a screening-based strategy (prenatal GBS cultures) and a strategy targeting prematurely born neonates offers a comprehensive method for prevention of early-onset GBS disease (Fig 1). Either of two maternal risk factors, previous delivery of an infant with invasive GBS disease or GBS bacteriuria during the current pregnancy, necessitates routine intrapartum chemoprophylaxis^1,2,4,6 with penicillin G intravenously. No prenatal screening is recommended.

View larger version (32K): [in this window] [in a new window]   Fig. 1.   Prevention strategy for early-onset GBS disease using prenatal culture screening at 35 to 37 weeks of gestation.

To improve the predictability of GBS colonization at delivery, lower vaginal and anorectal screening cultures for group B streptococcus are performed in all women at 35 to 37 weeks of gestation and processed in selective broth media.^1,6 Women who have preterm labor should have cultures performed to determine the presence of group B streptococcus and receive treatment with intravenous penicillin G, if delivery is anticipated. Management of preterm premature rupture of membranes and other obstetric considerations is addressed in the CDC and ACOG documents.^6,7 All women whose screening cultures are positive for group B streptococcus may choose prophylaxis, and GBS carriers with intrapartum fever or rupture of membranes 18 hours before delivery would be treated routinely. If screening cultures were not performed, or if results are unknown, women who have onset of labor before 37 weeks of gestation or have intrapartum temperature or ruptured membranes 18 hours before delivery would receive penicillin G, or if chorioamnionitis is suspected, other broader spectrum antimicrobial agents. Women without these risk factors or women with screening cultures negative for group B streptococcus do not require chemoprophylaxis.

This combination strategy has not been evaluated in large-scale trials, although treatment of all GBS carriers identified at 32 weeks of gestation was assessed in the Australian trial.¹⁸ Boyer et al¹⁴ found that the predictive value of screening cultures increased directly with proximity to delivery. Rouse et al¹² estimated that this combination strategy would result in intrapartum chemoprophylaxis for 26.7% of pregnant women and would prevent nearly 90% of cases. Furthermore, the strategy offers several potential advantages over exclusive reliance on either a culture screening-based or a risk factor-only approach.^6,7 Because cultures would be performed later in pregnancy, the false-negative rate would be negligible, and women receiving prenatal care late in pregnancy would be screened. All GBS carriers are offered intrapartum chemoprophylaxis, which enhances the likelihood that more than two doses will be given before delivery, in time for adequate antibiotic levels to be reached in the amniotic fluid.^25,26

	RISK FACTOR ONLY-BASED APPROACH

The strategy of treating all women with risk factors (Fig 2) is favored by some obstetric caregivers^4,5 and has been estimated to prevent 68.8% of cases of early-onset disease while administering prophylaxis to 18.3% of women in labor,⁶ based on the decision analysis by Rouse et al.¹² The consensus developed by the CDC, ACOG, and AAP considers the strategy of administering chemoprophylaxis to all women with risk factors without culture screening to be an equally acceptable alternative.^6,7

View larger version (19K): [in this window] [in a new window]   Fig. 2.   Prevention strategy for early-onset GBS disease using risk factors without prenatal culture screening.

Timing of Intrapartum Chemoprophylaxis

The number of doses of penicillin G received and the duration of intrapartum chemoprophylaxis are considered important factors in the prevention of neonatal GBS disease.²⁷ Theoretically, this will prevent the maximum number of infant cases of GBS disease and eliminate the morbidity and cost attendant to infant laboratory evaluation, intravenous antibiotic administration, level II or III nursery care, and prolonged hospitalization.

	MANAGEMENT OF NEWBORN INFANTS

The algorithm (Fig 3) for management of infants born to women receiving intrapartum chemoprophylaxis to prevent GBS disease is based on expert opinion; data to guide decision-making are limited. Evaluation of alternative approaches is encouraged. The management of infants born to women receiving chemoprophylaxis involves decision making concerning the following: (1) the presence or absence of signs compatible with systemic infection at birth, (2) the ability to assess signs, dictated by gestational age, (3) the number of doses of maternal chemoprophylaxis before delivery, and (4) the likelihood that features of early-onset GBS disease will occur within 48 hours of delivery.^2,8 Routine administration of antibiotics for all newborns born to mothers who receive intrapartum chemoprophylaxis to prevent GBS disease is not recommended.

View larger version (37K): [in this window] [in a new window]   Fig. 3.   Empiric management of neonate born to a mother who received intrapartum antimicrobial prophylaxis (IAP) for prevention of early-onset GBS disease.

Neonates at Any Gestation With Signs of Systemic Infection

Whether or not maternal intrapartum chemoprophylaxis is given, neonates with signs of septicemia should have a complete diagnostic evaluation and initiation of empiric antimicrobial therapy, usually with ampicillin and gentamicin. Laboratory evaluation should include a complete blood count (CBC) and differential cell count, a blood culture, and, if respiratory symptoms are present, a chest radiograph. Although elevated total white blood cell counts and absolute neutrophil counts are usually not helpful as single indicators of septicemia, neutropenia (total neutrophil cells, <1500/mm³) and an elevated immature-to-total (I:T) neutrophil ratio of >.20 are more often associated with systemic infection.²⁸ Although other perinatal conditions can elevate I:T ratios, this measurement has a 98% negative predictive value.²⁹ The value of a lumbar puncture is controversial,^30-32 and the need for this procedure should be determined by the examining physician. Additional laboratory studies, such as measurement of acute phase reactants²⁹ or testing of urine for GBS antigen, may be performed, but their predictive value is low, and perianal GBS contamination of urine specimens frequently produces a false-positive antigen result.³³

When antibiotic therapy is initiated, the duration of this empiric therapy will vary depending on the results of the initial CBC, blood culture, cerebrospinal fluid findings (if available), and the clinical course of the infant. If the laboratory evaluation and clinical course suggest that invasive infection is unlikely, therapy should be discontinued 48 to 72 hours after initiation.

Asymptomatic Infants of <35 Weeks of Gestation

Compared with term infants, premature neonates have a 10- to 15-fold increased risk for early-onset GBS septicemia.^2,8 Furthermore, as degree of prematurity increases, clinical evaluation to ascertain the presence or absence of signs of septicemia becomes more difficult. If the clinical evaluation is equivocal, it is appropriate for the physician to err on the side of implementing empiric therapy promptly. Asymptomatic infants <35 weeks of gestation should be evaluated and observed in the hospital without empiric antimicrobial therapy. The evaluation could be limited to a CBC (with differential) and a blood culture. At least 48 hours of hospital observation (ie, no early discharge) is indicated to minimize the likelihood of early-onset GBS septicemia after discharge. If during the period of observation the clinical course suggests systemic infection, complete diagnostic evaluation and initiation of empiric antibiotic therapy are indicated.

Asymptomatic Infants of 35 or More Weeks of Gestation

In infants with gestations of 35 weeks or longer, initial clinical evaluation of signs and symptoms should be more dependable. Thus, additional management would be dictated by the duration of maternal intrapartum chemoprophylaxis before delivery. Pylipow et al²⁴ found that all asymptomatic infants of GBS-colonized mothers who had received ampicillin intravenously >4 hours before delivery (eg, two or more doses) had normal laboratory evaluations and clinical courses without antimicrobial therapy. High amniotic fluid concentrations of ampicillin are achieved within 3 hours after intravenous administration.²⁵ Among the 43 infants whose mothers with GBS colonization had received only one dose of ampicillin, two had laboratory abnormalities (blood culture positive for group B streptococcus and positive urine GBS antigen test) that prompted antibiotic therapy for 10 days. The number of infants studied was low, but their data suggest that two or more doses of intrapartum ampicillin or penicillin G should prevent early-onset GBS septicemia. Thus, the algorithm recommends that asymptomatic infants who have a gestation of 35 weeks or longer and whose mothers have received two or more doses of penicillin G prophylaxis before delivery should receive routine newborn care with hospital observation for at least 48 hours. More than 95% of infants with early-onset GBS disease develop symptoms within 48 hours of birth,^2,8 and no instances of maternal chemoprophylaxis delaying onset of early neonatal GBS septicemia have been reported.

Asymptomatic Infants and the Number of Doses of Maternal Intrapartum Chemoprophylaxis Before Delivery

Term infants account for ~70% of cases of early-onset GBS septicemia in neonates, but the risk for sepsis and attendant mortality is lower than that in neonates born before 37 weeks of gestation.^2,8 Asymptomatic infants of 35 or more weeks of gestation whose mothers have received two or more doses of penicillin G should account for the majority requiring empiric management (Fig 3). They should be managed as healthy, low-risk newborns and do not require empiric laboratory evaluation or therapy. However, they should be observed in the hospital for at least 48 hours.

	FUTURE DEVELOPMENTS

Prevention of GBS disease ideally should be based on active immunization to induce protective immunity in the mother and newborn.² Immunization would be the most cost-beneficial prevention method¹¹ and would be long-lasting. Candidate vaccines are protein-polysaccharide conjugates that appear safe and antigenic in preliminary studies. Efficacy trials have not been performed.

	RECOMMENDATIONS

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1.  Obstetric care practitioners should adopt a strategy for the prevention of early-onset GBS disease in neonates. Patients should be informed regarding the available strategies for its prevention. Individual patient requests regarding GBS cultures should be honored. Insurance coverage for obstetric care should include payment for GBS cultures and at least 48 hours of nursery observation for at-risk newborns.
2.  Regardless of the preventive strategy used, women should be managed as follows:
     Women found to have symptomatic or asymptomatic GBS bacteriuria during pregnancy should be treated at the time of diagnosis. Because such women usually have heavy GBS colonization, they also should receive intrapartum chemoprophylaxis.
     Intrapartum chemoprophylaxis should be administered to women who have previously given birth to an infant with invasive GBS disease; prenatal culture screening is not necessary.
3.  Until additional data become available to define the most effective prevention strategy, either one of the following strategies is appropriate.

Prevention Strategy for Early-onset GBS Disease Using Prenatal Culture Screening at 35 to 37 Weeks of Gestation

All pregnant women at 35 to 37 weeks of gestation should be routinely screened for anogenital GBS colonization. All women identified as GBS carriers by culture should be offered intrapartum chemoprophylaxis even if a risk factor is not present.

If the results of GBS cultures are not known at the onset of labor or rupture of membranes, intrapartum antimicrobial prophylaxis should be administered if one of the following is present: gestation of <37 weeks, the membranes have been ruptured 18 hours or longer, or a temperature of 38°C (100.4°F) or greater.

Culture techniques that maximize the likelihood of GBS recovery should be used. The optimal method for GBS screening is collection of a single swab or two separate swabs of the distal vagina and anorectum followed by inoculation into selective broth medium, overnight incubation, and then subculture onto solid blood agar medium.

Oral antimicrobial agents should not be used to treat women who are found to have GBS colonization during prenatal screening. Such treatment is not effective in eliminating carriage or preventing neonatal disease.

Prevention Strategy for Early-onset GBS Disease Using Risk Factors Without Prenatal Culture Screening

A prevention strategy based on the presence of intrapartum risk factors without culture screening (eg, gestation of <37 weeks, duration of membrane rupture 18 hours, or temperature 38°C) is an acceptable alternative.4 For intrapartum chemoprophylaxis, intravenous penicillin G (5 million U initially and then 2.5 million U every 4 hours) should be given until delivery. Intravenous ampicillin (2 g initially and then 1 g every 4 hours until delivery) is an acceptable alternative, but penicillin G is preferred, because it has a narrow spectrum and is therefore less likely to select for antibiotic-resistant organisms. Intravenous clindamycin or erythromycin may be used for women allergic to penicillin.

5 Routine use of prophylactic antimicrobial agents for infants born to mothers who have received intrapartum chemoprophylaxis is not recommended. However, therapeutic use of these agents is appropriate for infants with clinically suspected sepsis. The duration of therapy in symptomatic infants varies depending on the results of blood culture, cerebrospinal fluid findings (if determined), and clinical course. If the laboratory evaluation and clinical course are inconsistent with a diagnosis of invasive infection, the duration of empiric therapy should be as short as 48 to 72 hours.

6 Guidelines regarding management of asymptomatic infants born to women given intrapartum chemoprophylaxis are empiric. The suggested approach given here is not an exclusive course of management. Other treatment modalities that take into account individual circumstances and individual physician or institutional preferences may be appropriate.
  For asymptomatic infants whose mothers have received intrapartum prophylaxis, those with gestations of <35 weeks should have a limited diagnostic evaluation (CBC [and differential] and blood culture) and be observed without antimicrobial therapy in the hospital for at least 48 hours (ie, does not allow for early discharge). If during hospital observation signs of systemic infection develop, a complete diagnostic evaluation should be performed, and antimicrobial therapy should be initiated.
  In asymptomatic infants with a gestational age of 35 weeks or longer, the duration of intrapartum prophylaxis before delivery determines subsequent management. If two or more doses of maternal prophylaxis were given before delivery, no laboratory evaluation or antimicrobial therapy is recommended. These infants should be observed in the hospital for at least 48 hours (ie, does not allow for early discharge). If only one dose of maternal prophylaxis was given before delivery, infants should have a limited evaluation and at least 48 hours of observation before hospital discharge.

7 Investigations designed to evaluate and compare these and other strategies are needed urgently to assess outcomes, including the incidence of neonatal GBS disease, occurrence of adverse reactions to antimicrobial prophylaxis, and the emergence of perinatal infections attributable to penicillin-resistant organisms. Characterization of prevention failures also is important.

COMMITTEE ON INFECTIOUS DISEASES, 1995 TO 1996
Neal A. Halsey, MD, Chairperson
P. Joan Chesney, MD
Michael A. Gerber, MD
Donald S. Gromisch, MD
Steve Kohl, MD
S. Michael Marcy, MD
Melvin I. Marks, MD
Dennis L. Murray, MD
James C. Overall, Jr, MD
Larry K. Pickering, MD
Richard J. Whitley, MD
Ram Yogev, MD
EX-OFFICIO
Georges Peter, MD
CONSULTANT
Carol J. Baker, MD
LIAISON REPRESENTATIVES
Ruth L. Berkelman, MD
Centers for Disease Control and Prevention
Robert Breiman, MD
National Vaccine Program Office
M. Carolyn Hardegree, MD
Food and Drug Administration
Richard F. Jacobs, MD
American Thoracic Society
Noni E. MacDonald, MD
Canadian Paediatric Society
Walter A. Orenstein, MD
Centers for Disease Control and Prevention
N. Regina Rabinovich, MD
  National Institutes of Health
COMMITTEE ON FETUS AND NEWBORN, 1996 TO 1997
William Oh, MD, Chairperson
Lillian R. Blackmon, MD
Avroy A. Fanaroff, MD
Barry V. Kirkpatrick, MD
Hugh M. MacDonald, MD
Carol A. Miller, MD
Lu-Ann Papile, MD
Craig T. Shoemaker, MD
Michael E. Speer, MD
LIAISON REPRESENTATIVES
Patricia Johnson, RN, MS, NNP
  American Nurses Association
  Association of Women's Health, Obstetric, and   Neonatal Nurses
  National Association of Neonatal Nurses
Michael F. Greene
  American College of Obstetricians and Gynecologists
Douglas D. McMillan, MD
  Canadian Paediatric Society
Diane Rowley, MD, MPH
  Centers for Disease Control and Prevention
Linda L. Wright, MD
  National Institute of Child Health and Human   Development
AAP SECTION LIAISON
Jacob C. Langer, MD
  Section on Surgery

	FOOTNOTES

The recommendations in this statement do not indicate an exclusive course of treatment or serve as a standard of medical care. Variations, taking into account individual circumstances, may be appropriate.

	ABBREVIATIONS

AAP, American Academy of Pediatrics. GBS, group B streptococcal. ACOG, American College of Obstetricians and Gynecologists. CDC, Centers for Disease Control and Prevention. CBC, complete blood count. I:T, immature-to-total ratio.

	REFERENCES

Top Abstract Recommendation References

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4. American College of Obstetricians and Gynecologists Group B streptococcal infections in pregnancy: ACOG's recommendations. ACOG Newsletter. 1993; 37:1
5. Jafari HS, Schuchat A, Hilsdon R, Whitney CG, Toomey KE, Wenger JD Barriers to prevention of perinatal group B streptococcal disease. Pediatr Infect Dis J. 1995; 14:662-667 [Medline]
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