Background: Recommendations for the use of antenatal antibiotics have been widely implemented in the past few years, notably to prevent group B streptococcal disease or to prolong pregnancy in the case of preterm premature rupture of the membranes.
Objectives: We designed a retrospective study to assess the potential effects of this increasing use of antibiotics on the incidence and bacteriological profile of early-onset neonatal sepsis (EONS).
Methods: All neonates referred to our department for suspected EONS from January 1 1995 through December 31 1999 were included. Antenatal antibiotic exposure together with clinical and microbiological data from the neonatal period were gathered and analyzed on a yearly basis.
Results: Of the 485 newborns who met the inclusion criteria, there were 101 cases of culture-confirmed sepsis; 339 cases of suspected sepsis and 69 cases of confirmed sepsis involved children born in the hospital, among a total of 16,627 live births registered in our center over the study period. The overall incidence of EONS dropped from 6.8 to 0.6/1,000 births between 1995 and 1999 (p < 0.001), but the rate of group B streptococcal infection decreased much more rapidly than that of non-group B streptococcal infection. We observed a trend towards the emergence of ampicillin-resistant Escherichia coli strains, which were isolated in seven cases. Among E. COLI infections, ampicillin resistance was statistically linked with antenatal antibiotic use (p = 0.025). We also delineated several risk factors associated with these infections.
Conclusion: In our center, antenatal antibiotic treatment was effective in reducing the incidence of EONS, but this benefit may come at the cost of favoring the emergence of ampicillin-resistant organisms causing severe neonatal infections. Antenatal and postnatal antibiotic treatment strategies should take this adverse effect into account.
Copyright 2003 S. Karger AG, Basel