From Medscape today... Neonatal Group B Streptococcal Disease Prevention Gilles R. G. Monif, MD In 1996, guidelines for the prevention of neonatal group B streptococcal disease were issued by the American College of Obstetricians and Gynecologists, the American Academy of Pediatrics, and the CDC. Two approaches were advocated to identify candidates for intrapartum antibiotic prophylaxis. The first of these was a maternal risk-based approach in which intrapartum antibiotics would be administered to pregnant women with preterm deliveries, prolonged rupture of the fetal membranes, intrapartum fever, prior neonatal disease caused by group B Streptococcus (GBS), or GBS bacteriuria. The second was a bacteriologic screening approach that entailed obtaining cultures from pregnant women to check for vaginal and rectal GBS carriage between 35 and 37 weeks of gestation and offering intrapartum chemoprophylaxis to those identified as being colonized. The latter approach was subsequently modified to include gravidas with GBS bacteriuria and women who had given birth to a GBS-infected neonate. Both approaches were recommended as equally acceptable. Schrag and colleagues (N Engl J Med. 2002;347:233-239) reported on a multistate retrospective cohort study involving 5144 births in which they compared the 2 officially recommended strategies. According to their univariate statistical analysis, prenatal screening for GBS was associated with a lower risk of early-onset neonatal disease than was the risk-based approach (relative risk, 0.48; 95% confidence interval, 0.38 to 0.61). Intrapartum maternal fever and previously having a neonate with GBS disease had the highest correlation with the risk of early-onset disease. Gravidas with GBS bacteriuria did not exhibit an increased risk; however, the significance of that finding was limited by the fact that the majority of these women were identified and treated within the bacteriologically screened group and, overall, 82% of women with GBS bacteriuria received intrapartum antibiotics. Using risk factors without significant screening for asymptomatic bacteriuria makes it more likely than not that the majority of gravidas with untreated GBS asymptomatic bacteriuria resided in the maternal risk-factor group. A key observation was the finding that in the screening group, 18% of all gravidas did not present with an identified maternal risk factor. The incidence of neonates with GBS disease born to mothers without risk factors was 1.3 per 1000 live births. The efficacy of intrapartum antibiotics in preventing early-onset disease among newborns born to culture-positive pregnant women without risk factors was close to 90%. The authors found that the screening approach for the prevention of neonatal GBS bacteriuria was more than 50% more effective than the risk-based approach. They therefore called for reconsideration of recommendations that endorse both strategies as equivalent. While well done, this study has inherent problems characteristic of retrospective studies using multiple sites. Which approach should be advocated may not be the key issue. Both approaches have significantly reduced GBS neonatal disease but have not eliminated it. The tight focus on the obstetric/perinatal aspects of disease has precluded development of a significant pediatric preventive intervention. Before the 1996 guidelines, universal administration of penicillin to all neonates profoundly altered the incidence of ensuing neonatal GBS disease. Unlike in pregnant women, anaphylaxis has not been described in a newborn (Obstet Gynecol. 1996;87:692-698). The drug per se is relatively inexpensive. Wendel and colleagues (Am J Obstet Gynecol. 2002;186:618-626) have calculated that almost 1400 neonates could receive single-dose prophylaxis with 50,000 units of penicillin G for the cost of a single successful treatment of 1 GBS-affected baby. Wendel and coauthors used an approach combining both risk factors and culture surveillance with universal neonatal penicillin administration to achieve excellent results in a high-risk population. They demonstrated that a protocol of intrapartum ampicillin given to pregnant women at risk for bearing neonates with GBS sepsis combined with routine penicillin G prophylaxis given to all other neonates dramatically reduced the incidence of GBS disease and did so without increasing the rate of sepsis from other bacteria. Such a strategy is the missing prevention approach in the CDC's comparative study. Without a pediatric component, no obstetric prevention program will meet society's mandate with respect to GBS disease prevention. Infect Med 20(8):370,373, 2003. (c) 2003 Cliggott Publishing, Division of SCP Communications --------- Katherine Shealy *********************************************** To temporarily stop your subscription: set lactnet nomail To start it again: set lactnet mail (or digest) To unsubscribe: unsubscribe lactnet All commands go to [log in to unmask] The LACTNET mailing list is powered by L-Soft's renowned LISTSERV(R) list management software together with L-Soft's LSMTP(TM) mailer for lightning fast mail delivery. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html