No change in the incidence of ampicillin-resistant, neonatal, early-onset sepsis over 18 years

Pediatrics. 2010 May;125(5):e1031-8. doi: 10.1542/peds.2009-1573. Epub 2010 Apr 12.


Objective: The objective of this study was to assess the effect of maternal antibiotic exposure on neonatal early-onset sepsis (EOS) rates over an 18-year period.

Methods: A review was performed of infant and maternal records for all culture- proven cases of EOS in infants delivered at the Brigham and Women's Hospital (Boston, MA) in 1990-2007.

Results: Data were analyzed from 335 EOS cases over periods that differed with respect to hospital policy for intrapartum antibiotic prophylaxis against group B Streptococcus (GBS): 1990-1992 (no prophylaxis); 1993-1996 (risk-based); and 1997-2007 (screening-based). The overall incidence of EOS decreased over these periods (3.70 vs 2.23 vs 1.59 cases per 1000 live births; P < .0001). No change in the incidence of infection with ampicillin-resistant organisms was observed overall or among very low birth weight infants. However, an increased proportion of infections were caused by ampicillin- resistant organisms. Mothers of infants with ampicillin-resistant infections were more likely to have been treated with ampicillin (P = .0001). Overall peripartum antibiotic use increased during the study period primarily because of increased use of penicillin G and clindamycin, with no significant change in the use of ampicillin.

Conclusions: Predominant use of penicillin G for GBS prophylaxis resulted in decreased incidence of EOS. No change in the incidence of ampicillin-resistant EOS was observed, but resistant cases were associated with peripartum ampicillin exposure. These findings suggest that obstetricians should consider preferential use of penicillin G for GBS prophylaxis.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Ampicillin Resistance*
  • Antibiotic Prophylaxis*
  • Bacteremia / drug therapy*
  • Bacteremia / epidemiology
  • Cross-Sectional Studies
  • Female
  • Humans
  • Incidence
  • Infant, Newborn
  • Infant, Premature, Diseases / drug therapy*
  • Infant, Premature, Diseases / epidemiology
  • Infant, Premature, Diseases / microbiology
  • Infant, Very Low Birth Weight*
  • Male
  • Microbial Sensitivity Tests
  • Pregnancy
  • Prenatal Exposure Delayed Effects / drug therapy*
  • Prenatal Exposure Delayed Effects / epidemiology
  • Retrospective Studies
  • Sepsis / drug therapy*
  • Sepsis / epidemiology
  • Sepsis / microbiology
  • Streptococcal Infections / drug therapy*
  • Streptococcal Infections / epidemiology
  • Streptococcal Infections / prevention & control
  • Streptococcus agalactiae*