Risk factors associated with early-onset sepsis in premature infants.

Objective: To define perinatal factors associated with early-onset neonatal sepsis.

Study Design: Maternal and neonatal variables were analysed retrospectively in 343 infants born before 35 weeks using univariate and multivariate statistical analysis.

Results: Logistic regression analysis identified risk factors for probable neonatal sepsis: gestational age at delivery (odds ratio 0.9, 95% confidence interval (CI) 0.91-0.96), premature rupture of the membranes (odds ratio 2.9, 95% CI 1.004-8.56), Apgar score after 1 min (odds ratio 0.7, 95% CI 0.53-0.96), and histological chorioamnionitis and/or funisitis (odds ratio 4.1, 95% CI 1.36-12.12). There was a strong association between probable sepsis and intracranial haemorrhage of the infant (odds ratio 4.3, 95% CI 1.07-17.40). Funisitis had a high specificity (91%) and positive predictive value (82%) for the detection of neonatal sepsis < or =32 weeks.

Conclusions: Independent obstetrical risk factors for early-onset neonatal sepsis in premature infants may help to identify newborns who benefit from maternal antibiotic prophylaxis before birth. The histological examination of the umbilical cord can be used as an additional diagnostic test to detect newborns at risk of infection.