Fetal fibronectin as a predictor of term labor: A literature review

Objective. Accurately predicting the onset of delivery continues to be problematic notwithstanding the clinical relevance of this capability, especially with regard to the elective induction of labor. While the assessment of the cervix according to Bishop, to date, constitutes the single generally recognized method, the determination of fetal fibronectin (FFN) cervicovaginal secretions promises greater precision in this context. Design. English-language medical literature was analyzed using the search parameter 'fetal fibronectin', 'term delivery', 'induction of labor', 'labor', and 'birth', respectively. All those original reports examining cervicovaginal FFN that were originally published in English and followed a prospective design were subsequently included in the study at hand. These reports were evaluated in regard to their findings on the predictive value of FFN for spontaneous delivery and induction of labor. Results. A total of eight reports were included in the present study: five of these, covering a total of 480 patients, discussed the relationship between FFN and the spontaneous onset of labor; the other three addressed the subject of FFN and the induction of labor (300 patients). All reports clearly related the presence of FFN in cervicovaginal secretions to the imminent onset of delivery; three studies, furthermore, demonstrated a correlation with the spontaneous onset of labor, with a sensitivity greater than 90%. In case of the studies concerning induction of labor, a positive FFN result was accompanied by a significantly shorter interval until delivery than a negative FFN result. Conclusion. Determining the presence of FFN in cervicovaginal secretions promises to provide an indicator relating to the prediction of term labor, as well as to the prediction of successful labor induction.