Linking fetal fibronectin to labor induction

Can measuring fetal fibronectin (fFN) help predict the success of labor induction? Two studies presented at ACM tried to answer that question. In an observational study that looked at 235 women undergoing preinduction cervical ripening, 55% finally delivered vaginally, but a positive fFN (>50 ng/mL) wasn't able to signal a successful labor induction. Despite this disappointing news, women with a positive fFN did require less oxytocin and had shorter induction times.

On a more positive note, a multi-center clinical trial sponsored by the makers of the fFN test, which enrolled 875 women, suggested that a positive test did in fact predict a successful labor induction. About 43% of women with a positive reading entered active labor, compared to 17.4% who had a positive fFN with a failed induction.

Deluca S, Benson J, Vakili B, et al. Fetal fibronectin and the prediction of vaginal delivery in nulliparous women undergoing labor induction. Obstet Gynecol. 2004;103(4 suppl): 69S.

Yeast JD, Hickok D, Williams C. A positive fetal fibronectin test is associated with a reduced risk of failed induction. Obstet Gynecol. 2004;103(4 suppl):70S.