Phosphorylated insulin-like growth factor binding protein-1 in cervical secretions and sonographic cervical length in the prediction of spontaneous preterm delivery.

OBJECTIVES

The aim of this study was to evaluate the efficacy of the test for the decidual phosphorylated isoform of insulin-like growth factor binding protein-1 (phIGFBP-1) in endocervical secretions in predicting preterm delivery in women with uterine contractions.

METHODS

The study included 210 women with a singleton pregnancy with documented uterine contractions and intact membranes at between 24 and 34 weeks' gestation who underwent the cervicovaginal phIGFBP-1 test and transvaginal sonographic measurement of cervical length. A receiver-operating characteristics (ROC) curve was used to determine the most useful cut-off point for cervical length. A multivariate logistic regression model was used in order to analyze the combination of significant predictive variables for preterm delivery following univariate analysis.

RESULTS

ROC curves indicated that 26 mm was the optimal cut-off value for cervical length in predicting preterm delivery. A cervical length of < 26 mm and the presence of phIGFBP-1 were statistically significant in univariate logistic regression analyses (P < 0.0001) with odds ratios of 16.18 and 9.29 for preterm delivery, respectively. Multivariate analysis of cervical length and phIGFBP-1 showed that they were independent and therefore useful in combination for predicting preterm delivery.

CONCLUSIONS

Cervical length and the phIGFBP-1 test are independent variables that can be used together to predict preterm delivery in women with uterine contractions. A sonographically measured cervical length of > 26 mm with a negative phIGFBP-1 test in a patient with regular uterine contractions before 37 weeks' gestation seems to indicate a low risk of preterm delivery and may therefore allow avoidance of unnecessary therapies.