Improved Management in Threatened Preterm Labor With Rapid Fetal Fibronectin Testing

Abstract

An estimated 80% of women with threatened preterm labor will go on to deliver at term. Nevertheless, the sequelae of preterm delivery are so threatening that affected women routinely are assessed by ultrasound and receive steroids as well as acute tocolytic therapy in the hospital. Estimating levels of fetal fibronectin (fFN) clearly has some predictive value, notably a negative predictive value of 99.5% for delivery within 1 week. Until now, fFN has been estimated using an enzyme-linked immunosorbent assay (ELISA), an expensive and time-consuming procedure. A new optical system, the TLIIq photometer, has a turnaround time of only 20 minutes and appears to be as accurate as the ELISA. Studies done to date to evaluate the TLIIq have given mixed results. In a 3-month period before the TLIIq system became available, 11 women met criteria for fFN testing. Gestational ages ranged from 27 to 33 weeks and gestational ages at delivery from 30 to 40 weeks. Nine other women, tested in a second 3-month period using the TLIIq system, had initial gestational ages from 25 to 34 weeks and gestational ages at delivery of 30 to 41 techniques. The rate of ultrasound study fell from 100% to 78% in the later period. Steroids were administered to 82% and 56% of women, respectively, and tocolytic therapy to the same proportions. The average hospital stay declined from 3.8 to 2.5 days. Of 6 TLIIq-negative women, 4 had ultrasound studies, 2 received steroids, 2 received tocolytic therapy, and the time in the hospital averaged 1.7 days. These prospectively collected findings, although on a small scale, suggest that a rapid test for fFN has the potential to limit time in the hospital for women with threatened preterm labor and thereby to confer emotional and social benefit.