Amniocentesis in the evaluation of premature labor.

Amniocentesis was performed to obtain amniotic fluid for culture in 25 patients undergoing tocolytic therapy for premature labor, all of whom had intact membranes. Three specimens yielded positive cultures, 2 of which were considered contaminants. The only patient with significant bacterial growth in the amniotic fluid also had clinical signs and symptoms suggestive of amnionitis. Five of the 25 patients (20%) experienced spontaneous rupture of membranes after amniocentesis. Based on the results of this study, amniocentesis solely for the confirmation of asymptomatic amnionitis in the patient in premature labor seems to be of questionable value.