Background: Intra-partum antibiotic prophylaxis (IAP) was shown to decrease the incidence of neonatal early onset sepsis (EOS) but it may mask the results of the neonate blood culture.
Objective: We studied in vitro the bactericidal effect of cord and peripheral blood of neonates whose mothers were treated IAP.
Methods: The bactericidal effect was tested against bacteria that were recovered from previous neonatal EOS. Bactericidal test was conducted upon 60 samples of umbilical blood and 18 samples of peripheral neonatal blood. As a control group we used 10 samples of cord blood from mothers without IAP.
Results: Cord blood exerted bactericidal effect against 98% of GBS isolates but only 8% of E. Coli isolates.
Bactericidal effect of the peripheral blood was found only against GBS, in 94% of the cases and it was found even 870 minutes after the antibiotic was given to the mother.
No bactericidal effect was seen in the control group.
Conclusions: The study showed that there is a bactericidal effect to umbilical and neonatal peripheral blood in IAP treated mothers. The results supports the AAP recommendation that asymptomatic newborns to GBS colonized mother that were treated IAP do not need treatment. When the blood cord was tasted on E.coli the bactericidal effect significantly decreased. This supports the fact that IAP did not result in a decrease in E. coli EOS, and that the blood cultures are more reliable. Yet, in a symptomatic newborn, even with a negative blood culture, cessation of antibiotic treatment should consider more carefully.
