Amniocentesis in the identification of inapparent infection in preterm patients with premature rupture of the membranes.

Twenty-nine preterm patients with premature rupture of the membranes who were not in labor and who did not have clinical chorioamnionitis underwent successful amniocenteses. Nine fluids were positive for bacteria. Subsequent clinical chorioamnionitis and shorter latency periods were more common in these 9 patients than in the 20 with sterile amniotic fluid. Positive fluids were more likely to be obtained from patients tapped within 48 hours of membrane rupture. In most patients with heavy bacterial growth, clinically apparent infection and/or labor soon supervened.