Fetal Fibronectin Test Performance in Patients at Low Risk for Preterm Delivery

Sumithra Jeganathan,Aleksandr M Fuks,Alexander G Shilkrut,Sari J Kaminsky

doi:10.15296/ijwhr.2020.56

Abstract

Objectives: Spontaneous preterm birth is a leading cause of neonatal death. Fetal fibronectin (fFN) testing in cervical secretions between 22-34.6 weeks of gestation is used to predict non-delivery within the next 7 days in patients with symptoms of preterm labor. The objective of this study is to analyze fFN test performance in a group of patients with low risk for preterm delivery that presented with preterm labor symptoms, and to evaluate how the results of fFN testing influenced management decisions. Materials and Methods: Patients after preterm delivery (gestational age 24.0-36.6 weeks) and patients who underwent fFN testing in Metropolitan Hospital, NYC Health+Hospitals, New York, NY, from January 1, 2015 to December 31, 2015 were identified and reviewed. Patients with positive fFN test results (fFN+; >50 ng/dL) were compared to patients with negative fFN test results (fFN-). Results: Among 77 patients identified, 66 (86%) were fFN- and 11 (14%) fFN+; 15 patients (78%) who delivered preterm were not tested with fFN. Preterm birth rate during the study period was 1.9%. There was no difference in maternal or neonatal characteristics between the two groups. Among fFN-, 4 patients (6%) delivered preterm, while among fFN+, none delivered preterm. In both groups, none delivered within 7 days of testing. Compared to fFN-, fFN+ had higher rates of admissions (36% vs 0%; P<0.001) and steroid administration (82% vs 0%; P<0.001). Conclusions: In this retrospective analysis, use of fFN testing as an initial screening test for patients with symptoms of preterm labor in this low risk population did not result in improved clinical outcomes and was associated with a higher rates of hospital admissions and steroid administration.

Highlights

Spontaneous preterm birth is one of the leading causes of neonatal death with approximately one million preterm newborns dying every year.[1]
There were 98 Fetal fibronectin (fFN) tests performed during the study period and 21 patients were excluded from analysis
Of the patients excluded from analysis, 12 patients transferred prenatal care, 2 patients had extramural delivery, 1 patient was induced for preeclampsia, 1 patient had cerclage in situ, and 5 patients had twin gestation (Figure 1)

Summary

Introduction

Spontaneous preterm birth is one of the leading causes of neonatal death with approximately one million preterm newborns dying every year.[1] Symptoms of preterm birth are usually vague and nonspecific, and it is often a challenging task for clinician to identify which patients will deliver preterm.[2] Antenatal corticosteroids can be administered to decrease respiratory complications and improve survival rates to those at risk of preterm labor.[3] Preferably, corticosteroid should be given within 7 days of delivery.[2] Tocolytics can be used to delay onset of preterm labor for 48 hours to allow administration of corticosteroids, but beyond that, they have showed minimal benefit to the reduction of neonatal morbidity and mortality.[4] Admissions and transfers to a higher level of care centers for suspected preterm labor are often associated with inconvenience, loss of productivity and significant cost, it is important to develop clinical tests that would allow to identify reliably patients at risk for preterm labor

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Conclusion