The diagnosis of early preterm labor is difficult and is accompanied by a high false-positive rate. As many as 50% of subjects enrolled in the placebo arms of pro- spective, controlled trials of tocolytic medications will be delivered after 37 weeks.’ These false diagnoses result in unnecessary and potentially hazardous treatment for thousands of women annually. An improved method of early diagnosis would be a significant advance. Oncofetal fibronectin is an extracellular matrix pro-
From The Ohio State University,,” the University of Colorado Health