title: Prediction of spontaneous preterm birth by fetal fibronectin and uterine activity.
abstract: OBJECTIVE
  To evaluate the usefulness of fetal fibronectin and home uterine contraction assessment in predicting preterm birth (before 34 weeks) in at-risk asymptomatic women.
  
  
  METHODS
  One hundred fifty women were enrolled prospectively; five were lost to follow-up, leaving 145 women available for analysis. Because patients with preterm labor before 34 weeks' gestation most commonly develop this problem after 28 weeks, the period of 26-28 weeks' gestation was selected prospectively as the first window for prediction and study analysis. Eighty-five of 145 asymptomatic women at high risk for preterm birth had both home uterine contraction assessment of 2 hours per day and one or more cervical sampling(s) for fetal fibronectin measurement at 26-28 weeks. A positive home uterine contraction assessment was defined as contractions exceeding two per hour averaged over the 2-week study interval. Positive fetal fibronectin was defined as greater than 50 ng/mL.
  
  
  RESULTS
  Fourteen of the 85 women (16.5%) delivered before 34 weeks. Home uterine contraction assessment alone had a sensitivity, specificity, positive predictive value, and negative predictive value for preterm birth of 64, 85, 45, and 92%, respectively; fetal fibronectin alone was associated with values of 43, 89, 43, and 89%, respectively. A positive home uterine contraction assessment was associated with a relative risk (RR) for preterm birth of 5.9% (95% confidence interval [CI] 2.4-14.2), whereas a positive fetal fibronectin demonstrated an RR of 3.8 (95% CI 1.5-9.4). When both assessments were positive, all patients delivered before 34 weeks and there was an RR of 27.0 (95% CI 8.7-84.1) compared with those with both tests being negative. Only two patients with both tests negative delivered before 34 weeks (negative predictive value 96%).
  
  
  CONCLUSIONS
  Both the home uterine contraction assessment and fetal fibronectin accurately predicted preterm birth before 34 weeks. When both tests were combined, the predictive ability improved substantially.
authors.affiliation: Department of Obstetrics and Gynecology, University of Mississippi Medical Center, Jackson, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Morrison
authors.forename: R W
authors.initials: RW
authors.lastname: Naef
authors.forename: J J
authors.initials: JJ
authors.lastname: Botti
authors.forename: M
authors.initials: M
authors.lastname: Katz
authors.forename: J M
authors.initials: JM
authors.lastname: Belluomini
authors.forename: B N
authors.initials: BN
authors.lastname: McLaughlin
mesh_terms: D000328:Adult; D002584:Cervix Uteri / Q000737:chemistry; D005069:Evaluation Studies as Topic; D005321:Extraembryonic Membranes / Q000378:metabolism; D005260:Female; D005353:Fibronectins / Q000032:analysis*; D005865:Gestational Age; D006801:Humans; D007752:Obstetric Labor, Premature / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control; D011237:Predictive Value of Tests; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D011446:Prospective Studies; D012372:ROC Curve; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014590:Uterine Contraction
chemical_list: D005353:Fibronectins