Background Fetal fibronectin (fFN) testing is increasingly used to target women at risk of spontaneous preterm birth (sPTB) to determine corticosteroid administration, hospital admission and in utero transfer. Following its introduction into a tertiary referral center, we examined its use in high-risk asymptomatic women attending a preterm surveillance clinic (PSC) to determine its performance and effect on resources.

Methods All high-risk women (history of sPTB between 16–34 weeks, preterm pre-labour rupture of membranes, cervical surgery and congenital anomalies) attending the PSC for cervical length assessment had fFN testing between 23+0 and 34+6 weeks' gestation over a 1-year period.

Results Of the 811 visits to the PSC, 650 fFN tests were undertaken. Positive results were obtained in 11% (69/650) of visits and 32% resulted in steroid administration compared with 0.01% (4/581) with a negative result. Only 1 woman with a positive fFN received tocolysis. Positive results accounted for an admission rate of only 7.4% (48/650) in this high-risk cohort between 23+0 and 27+6 weeks' gestation. Outcome data was available for 544 fFN tests. 5.3% of women delivered at <34 weeks and 9.0% delivered at <37 weeks. fFN testing was associated with a positive (PPV) and negative predictive value (NPV) of 30.0% and 95.7% for delivery at <34 weeks' and 48.3% and 92.2% for delivery <37 weeks' gestation, respectively.

Conclusions The use of fFN testing in the PSC between 23+0 and 34+6 weeks' gestation has the potential to enhance the care algorithm of asymptomatic high-risk women by allowing appropriate targeted management.