Prediction of preterm delivery based on maternal plasma urocortin.

Context: Preterm birth still remains a significant management problem, and a large number of markers of the disease have been investigated.

Objective: We measured plasma levels of urocortin, a neuropeptide expressed by gestational tissues, in women with threatened preterm labor (TPTL) to evaluate whether the measurement may predict preterm delivery (PTD).

Design: We studied patients as part of an open observational study.

Setting: The study was conducted at a tertiary referral center for obstetric care.

Patients: Eighty-five women with singleton pregnancies between 28 and 34 completed gestational weeks with TPTL participated in the study.

Interventions: Interventions included clinical examination and urocortin measurement.

Main Outcome Measures: Pregnancy outcome and evaluation of sensitivity, specificity, and predictive values of urocortin as diagnostic test for PTD were measured.

Results: Thirty of 85 patients (35.3%) had PTD: 23 of 30 delivered within 7 d from admission (delivery time interval: 2.91 +/- 1.62 d; gestational weeks at delivery: 32.12 +/- 1.7); the remaining delivered later (delivery time interval: 11.71 +/- 4.27 d; gestational weeks at delivery: 33.5 +/- 2.18). Urocortin was significantly higher in women who delivered preterm (median 131.2 pg/ml, interquartile interval 115.1-139.4 pg/ml) than in those who progressed to term delivery [95.4 (69.9-101.3) pg/ml, P < 0.0001] and still higher in those delivering within 7 d from admission [137.7 (124.8-141.2) pg/ml]. Receiver operating characteristic curve analysis revealed that urocortin at the cutoff of 113.9 pg/ml had sensitivity of 80%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 90% as a marker for PTD.

Conclusions: Maternal plasma urocortin concentration is increased in patients with TPTL who have PTD, and its measurement may be a promising new biochemical marker of PTD.