Background: Guidelines for management of mother/infant pairs who received intrapartum antimicrobial prophylaxis (IAP) for prevention of EOGBSS, both from CDC (MMWR, 1996) and AAP (Pediatrics, 1997) recommend that infants ≥35 wks GA with inadequate IAP receive a complete blood count, a blood culture and all infants with maternal IAP remain in hospital ≥48 hrs. This practice may result in unwarranted intervention in asymptomatic infants. At Magee-Womens Hospital (MWH) asymptomatic infants≥35 wks GA born to mothers GBS positive (+) or unknown with risk factors (GBSURF) (RF=fever >38°C, PROM ≥18 hrs or delivery <37 wks GA) were observed for 36-48 hrs without laboratory evaluation regardless of IAP. The purpose of this study is to evaluate the introduction of these guidelines for prevention of EOGBSS into clinical practice.

Methods: Maternal GBS status, RF, IAP (adequate IAP= ≥4 hrs prior to delivery) and infant length of stay (LOS) was determined by chart review for asymptomatic infants≥35 wks GA born at MWH from 1/1/96-6/30/96. Prevalence of EOGBSS was compared before (1/1/92-6/30/95) and after (10/1/95-11/30/97) institution of CDC/MWH protocol by review of infant GBS+ blood cultures. Infant readmissions for EOGBSS were obtained by preliminary review of local hospital records.

Results: Of 3,501 asymptomatic infants ≥ 35 wks GA, 760 were born to mothers GBS+/GBS URF of whom 319 (42%) received either no or inadequate IAP. These 319 infants received no evaluation for sepsis. There was no clinically significant difference in LOS for infants of mothers GBS+/GBS URF (47hr±12) vs GBS-/unknown wo RF (46hr±13). The prevalence of EOGBSS was 1.15 per 1000 (36 of 31,133) live births before and 0.18 per 1000(3 of 16,508) live births after institution of CDC/MWH protocol. There were no readmissions with EOGBSS (0-0.02%, 95% CI).

Conclusion: This CDC/MWH strategy was associated with a >80% reduction in EOGBSS. Using this protocol, asymptomatic infants≥35 wks GA have no increase in LOS and no additional laboratory costs. Close surveillance for occurrence of EOGBSS after discharge is essential to confirm the safety of this protocol.