New approaches to the diagnosis of preterm labor

There is a pressing need to develop accurate methods of diagnosing true preterm labor because of the availability of potent tocolytic drugs and the known beneficial effects of antenatal glucocorticoid administration on neonatal outcomes of premature infants. Maternal plasma corticotropin-releasing hormone concentrations are elevated in women with threatened preterm labor between 28 and 36 weeks' gestation who give birth within 24 hours. In addition, the ratio of cortisol to corticosteroid binding capacity is elevated in the plasma of women who give birth within 24 hours. These data support the design and conduct of a prospective clinical trial to determine the positive and negative predictive Values of these markers for preterm birth in women with symptoms.