The Biomarkers for Preterm Birth Study-A prospective observational study comparing the impact of vaginal biomarkers on clinical practice when used in women with symptoms of preterm labor.

INTRODUCTION: This study aims to compare the use of qualitative fetal fibronectin, quantitative fetal fibronectin, and placental α-microglobulin-1 in women with symptoms of preterm labor, to evaluate which vaginal biomarker performs the best in clinical practice. MATERIAL AND METHODS: This prospective observational study included women who presented with symptoms of preterm labor at 24+0 to 34+0  weeks of gestation at a large tertiary maternity hospital in Auckland, New Zealand. Women were managed according to hospital guidelines using qualitative fetal fibronectin. Quantitative fetal fibronectin and placental α-microglobulin-1 tests were also taken, with clinicians blinded to the results. Management and delivery outcomes were collected from clinical records. The primary outcome was the rate of antenatal hospital admission. Analysis was performed according to predefined management protocols for each of the tests. RESULTS: A total of 128 women had all three biomarkers tests taken. Spontaneous preterm birth rates were 7/128 (5.5%) ≤34+0  weeks and 20/128 (15.6%) <37+0  weeks of gestation; 5/128 (3.9%) delivered within 7 days of testing. Positive results were recorded in 28 qualitative fetal fibronectin tests, 25 quantitative fetal fibronectin tests with 11 ≥200 ng/mL, and 16 placental α-microglobulin-1 tests. The use of quantitative fetal fibronectin or placental α-microglobulin-1 would have lowered antenatal admission rates: 27/128 (21.1%) for qualitative fetal fibronectin, 11/128 (8.6%) for quantitative fetal fibronectin (admission threshold ≥200 ng/mL), and 15/128 (11.7%) for placental α-microglobulin-1. No additional women with quantitative fetal fibronectin <200 ng/mL delivered within 7 days or missed corticosteroids compared with standard care (qualitative fetal fibronectin); however, an additional 3 cases had a false-negative placental α-microglobulin-1 and clinical care may have been compromised (no antenatal corticosteroids or admission). CONCLUSIONS: The use of quantitative fetal fibronectin (admission threshold ≥200 ng/mL) has the potential to reduce the rate of antenatal admissions for women with symptoms of preterm labor without compromising use of antenatal interventions that improve outcomes for babies born preterm.

Increasing compliance with a clinical practice guideline for fetal fibronectin testing and the management of threatened preterm labour: A quality improvement project.

OBJECTIVE: To increase adherence to a local hospital clinical practice guideline for the use of fetal fibronectin testing in women presenting with symptoms of threatened preterm labour. STUDY DESIGN: A quality improvement project using a multi-faceted implementation strategy. SETTING: National Women's Health, Auckland City Hospital; a tertiary referral maternity unit in Auckland, New Zealand. POPULATION: All obstetricians, junior obstetric doctors and hospital employed midwives. METHODS: A pre-education audit and survey, compulsory interactive educational intervention with audit feedback and provision of reminders followed by a post-education audit and survey one year later. MAIN OUTCOME MEASURES: Number of fetal fibronectin tests performed, proportion of tests performed meeting clinical criteria for testing and proportion of results managed according to hospital guideline. RESULTS: There was a 25% increase in the number of tests performed with an increase in the proportion that met clinical criteria for testing, 76% (31/41)-93% (51/55) (OR 4.1, 95% CI 1.2-14.2). Adherence to guidelines for clinical management according to fFN results changed over time, 80% (33/41)-95% (52/55) (OR 4.2, 95% CI 1.04-17.0). Clinician knowledge on some (but not all) indications for fFN testing improved. Education and reminders did not improve understanding of clinical scenarios that may result in a false positive fFN test. CONCLUSIONS: A multi-faceted approach of audit and clinician feedback, interactive education and reminders supports the implementation of a clinical practice guideline for the use of fFN as a preterm birth prediction test for women presenting with symptoms of threatened preterm labour.