Plasma CRH measurement at 16 to 20 weeks' gestation does not predict preterm delivery in women at high-risk for preterm delivery

Objective: The purpose of this study was to examine the utility of a single second- trimester plasma corticotropin-relasing hormone measurement as a marker for preterm delivery in women at high risk for preterm delivery. Study design: This is an analysis of data from a multicenter placebo-con trolled trial designed to evaluate the role of 17 alpha hydroxyprogesterone caproate (17P) in the prevention of recurrent preterm birth. Women with a documented history of a previous spontaneous preterm birth at < 37 weeks were enrolled (16-20 wks) and randomly assigned in a 2 to I ratio to weekly injections of 17P or matching placebo. Blood was collected before treatment in 170 patients (113 assigned 17P and 57 placebo) who were enrolled at I I of the 19 centers. Plasma levels of corticotropin-releasing hormone were compared between those who delivered preterm and those delivering at term. Data were analyzed using the Wilcoxon rank-sum test. Results: The overall rates of preterm birth in this cohort of 170 patients were 35.9% at < 37 weeks (31.9% progesterone, 43.9% placebo), and 19.4% at < 35 weeks (18.6% vs 2 1. 1 %). The median levels of corticotropin-releasing hormone were similar between those delivering at < 37 weeks and those delivering >= 37 weeks (0.39 ng/mL vs 0.37 ng/mL, P = .08). In addition, there were no differences in corticotropin-releasing hormone levels among those who delivered at < 35 weeks or >= 35 weeks (0.36 vs 0.38, P =.90). Moreover, there were no differences in corticotropin-releasing hormone levels among those in the placebo group who delivered at < 37 or >= 37 weeks (0.40 vs 0.41, P = .72) and at < 35 or >= 35 weeks (P = .64). Conclusion: A single measurement of corticotropin- releasing hormone at 16 to 20 weeks' gestation is not a good biomarker for recurrent preterm delivery in patients at high risk for this complication. (C) 2005 Mosby, Inc. All rights reserved.