Objective The Actim Partus test has been shown to be a useful predictor of preterm birth in symptomatic women but it has not been assessed in high-risk asymptomatic women. This is the first study to evaluate the use of this test in this population and to compare it to the fetal fibronectin (fFN) test.

Study Design All asymptomatic high-risk women attending a Preterm Surveillance Clinic at St Thomas' Hospital, London over a 9-month period had an Actim Partus and fFN test undertaken.

Results 69 patients were eligible. The positive predictive value (PPV) and negative predictive value (NPV) of the Actim Partus test for delivery at ≤37 weeks' gestation for tests undertaken at 19+0–20+6 weeks' gestation were 60% and 39%. Women presenting at 23+0–24+6 week's had both Actim Partus and fFN tests undertaken. The PPV and NPV for the Actim Partus test were 0% and 70%, respectively. The PPV and NPV of fFN test was 67% and 79%, respectively.

Conclusion The Actim Partus test did not perform well as a predictor of preterm birth in high-risk asymptomatic population prior to 24 weeks gestation in this small study. fFN prediction was similar to previous studies. Actim Partus maybe most valuable in symptomatic women.