Corticotropin-releasing hormone, corticotropin-releasing hormone-binding protein, and activin A in maternal serum: Prediction of preterm delivery andresponse to glucocorticoids in women with symptoms of preterm labor

OBJECTIVE: The aim of this study was to determine prospectively whether ser um concentrations of corticotropin-releasing hormone, corticotropin-releasi ng hormone-binding protein, and activin A (1) predict preterm birth within 10 days of hospital admission or at <37 weeks' gestation among women with s ymptoms of preterm labor and (2) are affected by glucocorticoid therapy. STUDY DESIGN: Serum concentrations of corticotropin-releasing hormone and a ctivin A were measured in 94 women with symptoms of preterm labor between 2 4 and 34 weeks' gestation, and delivery outcomes were monitored. Corticotro pin-releasing hormone-binding protein concentrations were measured in 71 of these women. In a subgroup of 15 women the serum analytes were assayed in conjunction with estriol before and 12 to 24 hours after administration of dexamethasone. RESULTS: Forty-six percent (6/13) of the women who were delivered within 10 days of hospital admission had a raised serum corticotropin-releasing horm one level, but the predictive relationship was not significant (chi(2) = 1. 7; P = .2). Among the 31 women (including the 6 previously mentioned) who w ere delivered at <37 weeks' gestation, 39% (12/31) had a raised corticotrop in-releasing hormone level. Although a raised corticotropin-releasing hormo ne concentration was positively associated with delivery at <37 weeks' gest ation (chi(2) = 9; P = .003), the predictive diagnostic value was poor, wit h sensitivity, specificity, and positive and negative predictive values of 39%, 90%, 67%, and 75%, respectively. The serum concentrations of corticotr opin-releasing hormone-binding protein and activin A were unrelated to gest ational age at delivery. Dexamethasone markedly lowered the serum estriol l evel (P < .001) but had no effect on concentrations of corticotropin-releas ing hormone, corticotropin-releasing hormone-binding protein, and activin A . CONCLUSION: Serum concentrations of corticotropin-releasing hormone, cortic otropin-releasing hormone-binding protein, and activin A are not clinically useful for the prediction of preterm delivery among women with symptoms of preterm labor and are not affected by administration of glucocorticoids.