OBJECTIVE: To assess the accuracy of a single cervical fetal fibronectin test to predict spontaneous preterm delivery in an unselected antenatal population. DESIGN: A prospective blind cohort study. SETTING: Antenatal clinic of a teaching hospital in a Brussels semiurban area. PARTICIPANTS: An unselected group of 170 women followed at the antenatal clinic. METHODS: A single cervical sample was obtained between 24 and 33 completed weeks of pregnancy. The fibronectin test was compared with clinical evaluation and their predictive properties were assessed. RESULTS: Fifteen women were excluded from the analysis because of elective preterm delivery for medical indications or loss to follow up. Of the 155 remaining women, nine (7%) had a spontaneous preterm delivery. For a single fetal fibronectin test, the sensitivity was 26.7%, the specificity 95.7%, and the positive and negative predictive values 40.0% and 92.4%, respectively. The likelihood ratio of a positive was similar to that of clinical predictors of preterm birth (LR = 6.2; 95% CI 2.0-19.6). Sensitivities were low for both clinical criteria and the fetal fibronectin test. CONCLUSIONS: Because of low sensitivity in a low risk population, screening for preterm delivery should not be based on the result of a single fetal fibronectin test alone. However, due to its high specificity the test might be useful in avoiding unnecessary medical intervention.
OBJECTIVE: To assess the accuracy of a single cervical fetal fibronectin test to predict spontaneous preterm delivery in an unselected antenatal population. DESIGN: A prospective blind cohort study. SETTING: Antenatal clinic of a teaching hospital in a Brussels semiurban area. PARTICIPANTS: An unselected group of 170 women followed at the antenatal clinic. METHODS: A single cervical sample was obtained between 24 and 33 completed weeks of pregnancy. The fibronectin test was compared with clinical evaluation and their predictive properties were assessed. RESULTS: Fifteen women were excluded from the analysis because of elective preterm delivery for medical indications or loss to follow up. Of the 155 remaining women, nine (7%) had a spontaneous preterm delivery. For a single fetal fibronectin test, the sensitivity was 26.7%, the specificity 95.7%, and the positive and negative predictive values 40.0% and 92.4%, respectively. The likelihood ratio of a positive was similar to that of clinical predictors of preterm birth (LR = 6.2; 95% CI 2.0-19.6). Sensitivities were low for both clinical criteria and the fetal fibronectin test. CONCLUSIONS: Because of low sensitivity in a low risk population, screening for preterm delivery should not be based on the result of a single fetal fibronectin test alone. However, due to its high specificity the test might be useful in avoiding unnecessary medical intervention.
Authors: M Sean Esplin; Michal A Elovitz; Jay D Iams; Corette B Parker; Ronald J Wapner; William A Grobman; Hyagriv N Simhan; Deborah A Wing; David M Haas; Robert M Silver; Matthew K Hoffman; Alan M Peaceman; Steve N Caritis; Samuel Parry; Pathik Wadhwa; Tatiana Foroud; Brian M Mercer; Shannon M Hunter; George R Saade; Uma M Reddy Journal: JAMA Date: 2017-03-14 Impact factor: 56.272