title: Predictive Accuracy of Serial Transvaginal Cervical Lengths and Quantitative Vaginal Fetal Fibronectin Levels for Spontaneous Preterm Birth Among Nulliparous Women.
abstract: Spontaneous preterm birth is a leading cause of infant mortality. Prediction, largely based on prior pregnancy outcomes, is not possible in women pregnant for the first time.
  
  
  
  To assess the accuracy of universal screening to predict spontaneous preterm birth in nulliparous women using serial measurements of vaginal fetal fibronectin levels and cervical length.
  
  
  
  A prospective observational cohort study of nulliparous women with singleton pregnancies, from 8 clinical sites across the United States between October 2010 and May 2014. Women and clinicians were blinded to results unless cervical shortening less than 15 mm was identified.
  
  
  
  Transvaginal cervical length and quantitative vaginal fetal fibronectin levels were reviewed at 2 study visits 4 or more weeks apart.
  
  
  
  Spontaneous preterm birth at less than 37 weeks was the primary outcome. Cervical length and quantitative fetal fibronectin were considered independently and together at each visit. Measurement distributions were compared for spontaneous preterm birth vs all other births. Spontaneous preterm birth before 32 weeks was a secondary outcome.
  
  
  
  The study included 9410 women (median age, 27.0 [interquartile range, 9.0] years; 60.7% non-Hispanic white, 13.8% non-Hispanic black, 16.5% Hispanic, 4.0% Asian, and 5.1% other), of whom 474 (5.0%) had spontaneous preterm births, 335 (3.6%) had medically indicated preterm births, and 8601 (91.4%) had term births. Among women with spontaneous preterm birth, cervical length of 25 mm or less occurred in 35 of 439 (8.0%) at 16 to 22 weeks' gestation and in 94 of 403 (23.3%) at 22 to 30 weeks' gestation. Fetal fibronectin levels of 50 ng/mL or greater at 16 to 22 weeks identified 30 of 410 women (7.3%) with spontaneous preterm birth and 31 of 384 (8.1%) at 22 to 30 weeks. The area under the receiver operating characteristic curve for screening between 22 and 30 weeks for fetal fibronectin level alone was 0.59 (95% CI, 0.56-0.62), for transvaginal cervical length alone was 0.67 (95% CI, 0.64-0.70), and for the combination as continuous variables was 0.67 (95% CI, 0.64-0.70).
  
  
  
  Among nulliparous women with singleton pregnancies, quantitative vaginal fetal fibronectin and serial transvaginal ultrasound cervical length had low predictive accuracy for spontaneous preterm birth. These findings do not support routine use of these tests in such women.
authors.affiliation: Intermountain Healthcare, Salt Lake City, Utah2University of Utah Health Sciences Center, Salt Lake City.
authors.forename: M Sean
authors.initials: MS
authors.lastname: Esplin
authors.affiliation: University of Pennsylvania, Philadelphia.
authors.forename: Michal A
authors.initials: MA
authors.lastname: Elovitz
authors.affiliation: Ohio State University, Columbus.
authors.forename: Jay D
authors.initials: JD
authors.lastname: Iams
authors.affiliation: RTI International, Research Triangle Park, North Carolina.
authors.forename: Corette B
authors.initials: CB
authors.lastname: Parker
authors.affiliation: Columbia University, New York, New York.
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Wapner
authors.affiliation: Northwestern University, Evanston, Illinois.
authors.forename: William A
authors.initials: WA
authors.lastname: Grobman
authors.affiliation: University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Hyagriv N
authors.initials: HN
authors.lastname: Simhan
authors.affiliation: University of California at Irvine.
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Wing
authors.affiliation: Indiana University, Bloomington.
authors.forename: David M
authors.initials: DM
authors.lastname: Haas
authors.affiliation: Intermountain Healthcare, Salt Lake City, Utah2University of Utah Health Sciences Center, Salt Lake City.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Silver
authors.affiliation: Christiana Care, Newark, Delaware.
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Hoffman
authors.affiliation: Northwestern University, Evanston, Illinois.
authors.forename: Alan M
authors.initials: AM
authors.lastname: Peaceman
authors.affiliation: University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Steve N
authors.initials: SN
authors.lastname: Caritis
authors.affiliation: University of Pennsylvania, Philadelphia.
authors.forename: Samuel
authors.initials: S
authors.lastname: Parry
authors.affiliation: University of California at Irvine.
authors.forename: Pathik
authors.initials: P
authors.lastname: Wadhwa
authors.affiliation: Indiana University, Bloomington.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Foroud
authors.affiliation: Case Western Reserve University, Cleveland, Ohio.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Mercer
authors.affiliation: RTI International, Research Triangle Park, North Carolina.
authors.forename: Shannon M
authors.initials: SM
authors.lastname: Hunter
authors.affiliation: University of Texas Medical Branch, Galveston.
authors.forename: George R
authors.initials: GR
authors.lastname: Saade
authors.affiliation: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), Bethesda, Maryland.
authors.forename: Uma M
authors.initials: UM
authors.lastname: Reddy
mesh_terms: D000293:Adolescent; D000328:Adult; D019540:Area Under Curve; D015415:Biomarkers / Q000032:analysis; D054791:Cervical Length Measurement / Q000379:methods*; D002584:Cervix Uteri / Q000033:anatomy & histology*; D005260:Female; D005333:Fetus; D005353:Fibronectins / Q000032:analysis*; D005865:Gestational Age; D006801:Humans; D010298:Parity; D011237:Predictive Value of Tests; D011247:Pregnancy; D047928:Premature Birth / Q000175:diagnosis* / Q000208:ethnology; D011446:Prospective Studies; D012372:ROC Curve; D014621:Vagina / Q000737:chemistry*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D005353:Fibronectins