[Identification of preterm labor: the role of the fibronectin and ultrasound cervicometry and their association].

OBJECTIVE: The aim of this study was to evaluate the effectiveness of the fetal fibronetcin (fFN) test and ultrasonographic cervical length measurement used alone or in combination with each other in order to further improve the identification of patients in preterm labor.

METHODS: Prospective multicenter observational study on patients between 24 and 32 weeks of gestation with symptoms of preterm labor (total patients = 132). The endpoint was the delivery at 34 weeks or more. The screening methods used were: the fFN test (group 1), the cervical length measurement by transvaginal ultrasound (group 2) or a combination of both tests (group 3) according to an established protocol. The statistical analysis was performed using the χ2 test using the SPSS software.

RESULTS: Group 1: positive fFN test in 25.7% of cases, incidence of preterm birth (<34 weeks) of 18%. Group 2: cervical length <25 mm in 56.2% of cases, incidence of preterm birth (<34 weeks) of 18.5%. The negative predictive value is equivalent to 99.0% for the fFN test and 95.2% for cervicometry; combined use reaches 100%, compared to 54% positive predictive value.

CONCLUSION: The identification of women at high risk of preterm delivery carried out with the fFN test or with transvaginal ultrasound cervicometry is clinically valid. The study also showed that the contextual use of biochemical and biophysical tests reaches a high negative predictive value (100%), making it a very useful method to identify patients truly at risk and to further reduce the incidence of non adequate treatment.