Epidemiology and risk factors for early onset sepsis among very-low-birthweight infants

Objective

The purpose of this study was to determine the incidence, causative pathogens, and risk factors for early onset sepsis (EOS) among very-low-birthweight (VLBW) infants.

Study Design

This was a population based observational study. Data were prospectively collected by the Israel Neonatal Network between 1995 and 2005. Multivariable analyses identified independent risk factors for EOS.

Results

EOS developed in 383 of 15,839 infants (2.42%). Fifty-five percent of pathogens isolated were gram-negative bacteria. Lack of prenatal care (odds ratio [OR], 1.94; 95% confidence interval [CI], 1.32-2.86), delivery room resuscitation (OR, 2.49; 95% CI, 1.91-3.24), membrane rupture > 24 hours without amnionitis (OR, 2.10; 95% CI, 1.53-2.88), amnionitis with membrane rupture < 24 hours (OR, 4.28; 95% CI, 2.97-6.16), and amnionitis with membrane rupture ≥ 24 hours (OR, 8.15; 95% CI, 5.98-11.10) were associated with EOS, but not antenatal steroids or gestational age.

Conclusion

EOS was caused mainly by gram-negative bacteria. Prolonged rupture of membranes and amnionitis have an additive effect on EOS with an above 8-fold excess risk when both were present.

Key words: amnionitis, early onset sepsis, prolonged rupture of membranes, risk factors, very-low-birthweight infant