Histologic chorioamnionitis prevalence in patients with premature rupture membranes.

: This was a retrospective cohort study between 2002 and 2011. A total number of 150 singleton pregnancies with preterm premature rupture of membranes (PROM) (before 34 weeks) were analyzed. Histological chorioamnionitis (Blanc grade III) was significantly increased over three days from onset of premature rupture of membranes. The positive relationship was strengthened (odds ratios, 3.5; 95% confidence intervals, 1.5-5.2) over three days from onset of preterm PROM. PROM is a risk factor important for histological chorioamnionitis. To avoid neonatal infection, early termination is recommended in preterm PROM patients.