NEW YORK (Reuters Health) – In pregnant women colonized with group B streptococcus (GBS) and at high risk for penicillin anaphylaxis, intrapartum prophylaxis with clindamycin to prevent perinatal GBS disease in the infant may be used, but only if the GBS isolate has been shown to be susceptible; if not, vancomycin should be used.

That’s one of the points emphasized in a Policy Statement on the prevention of perinatal GBS disease, published by the American Academy of Pediatrics in the September issue of Pediatrics, released online August 1.

The statement aims to highlight the differences between the 2002 guidelines and the 2010 update on this topic. The AAP’s Committee on Infectious Diseases and Committee on Fetus and Newborn note that the 2002 recommendation for universal antenatal GBS screening and intrapartum antibiotic prophylaxis if needed has cut the incidence of GBS disease in neonates by 80%.

The 2010 update aims to address potentially modifiable reasons for continued GBS perinatal disease. It includes “new recommendations for laboratory methods for identification of GBS colonization during pregnancy, algorithms for screening and intrapartum prophylaxis for women with preterm labor and premature rupture of membranes, updated prophylaxis recommendations for women with a penicillin allergy, and a revised algorithm for the care of newborn infants.”

For diagnosis of GBS colonization, the panel notes that the original recommendation for culture-based screening has been expanded to include the use of chromogenic agar media and identification of GBS directly by nucleic acid amplification tests (NAATs), such as commercially available PCR assays. No test is perfect, however, so newborns with signs of sepsis should be treated with antibiotics regardless of the maternal screening results.

For intrapartum prophylaxis, antibiotics should be given for at least 4 hours, and penicillin remains the agent of choice with ampicillin as an alternative. Women with penicillin allergy at low risk for anaphylaxis should be treated with cefazolin, the authors advise. For those at high risk, as mentioned, the options are clindamycin or vancomycin.

If newborns have signs of sepsis despite these measures, they should undergo a lumbar puncture if feasible, as up to 38% of infants with early-onset meningitis have sterile blood cultures, according to the paper.

Well-appearing infants whose mothers received adequate prophylaxis require only routine care and observation for 48 hours. The statement also addresses management when the mother has had inadequate prophylaxis, when chorioamnionitis has been diagnosed, and when premature rupture of membranes has occurred.

Reference:
Recommendations for the Prevention of Perinatal Group B Streptococcal (GBS) Disease
Pediatrics 2011;128.