Fig 5.

Receiver operator characteristic curves for plasma corticotrophin-releasing hormone levels and prior preterm birth history at 24 weeks based on delivery outcome of (A) <37 weeks and (B) <35 weeks. Green line = CRH alone. Red line = preterm birth history alone. Blue line = combination of CRH and prior preterm birth history. Area under the curve (AUC) statistics is 0.68 (95% CI 0.59–0.78) and 0.70 (95% CI 0.59–0.81) for CRH alone, at 24 (N = 169) and 32 (N = 113) weeks respectively, and 0.81 (95% CI 0.73–0.88, P = .001) for delivery <37 weeks and 0.82 (95% CI 0.74–0.91) for <35 weeks when CRH and prior preterm birth history are combined. The AUC combining CRH and prior preterm birth history is significantly different than that with CRH alone (P = .001 for <37 weeks and < .001 for <35 weeks).