Premature rupture of the membranes and sepsis in preterm neonates.

This investigation was designed as a historical cohort study using data abstracted from medical records. Five hundred seven preterm neonates (26-35 weeks gestation) born alive from singleton pregnancies complicated by premature rupture of the membranes (PROM) were selected. Each neonate was matched on gestational age, gender, ethnicity, and date of delivery to a neonate without PROM. A matched pairs analysis was done using risk ratios (RR) to measure strength of the association and risk differences (RD) to measure absolute effect. Analysis revealed that preterm births complicated by PROM were at significantly higher risk of neonatal sepsis (RR = 3.5) and infection (RR = 2.4). The RDs indicated that PROM exposure contributed an excess of 5 cases of sepsis per 100 infants (RD = 0.05). PROM was not significantly associated with neonatal mortality, but when PROM had existed over 48 hours there was a higher risk of sepsis and infection. Birth of a neonate over 1500 grams or 33 weeks gestation was the most important factor in reducing risk of infection in PROM deliveries.