Can fetal fibronectin testing improve the management of preterm labour?

The detection of fetal fibronectin (Ffn) in cervico-vaginal secretions has been proposed as a method to differentiate true from false threatened preterm labour. This study evaluates the impact of tocolysis in the management of threatened preterm labour and compares actual practice in our department with a hypothetical management strategy based upon fetal fibronectin (Ffn) testing. Over a 12 month period, 41 women were admitted in threatened preterm labour with intact membranes before 34 weeks gestation. In "actual practice", 13 received tocolysis but only three cases were considered to have benefitted from it (ratio 4.3:1). In the Ffn strategy, 34 women would receive tocolysis with 12 potentially benefitting (ratio 2.8:1). If tocolysis was given to all eligible women ("non-selective" policy) 41 women would receive tocolysis with 12 potentially benefitting (ratio 3.4:1). The majority of women receiving tocolysis do not benefit from this treatment regardless of whether tocolysis is based upon clinical judgement. Ffn testing or a non-selective administration policy. Administering tocolysis on the basis of a positive Ffn result would be expected to increase the number of women receiving tocolysis but would make a small improvement in the treatment: potential benefit ratio when compared to "actual practice".