title: The negative predictive value of cervical interleukin-6 for the risk assessment of preterm birth.
abstract: OBJECTIVE
  To determine the potential clinical use of cervical interleukin-6 (IL-6) as a negative predictor of preterm birth in symptomatic women.
  
  
  METHODS
  Observational prospective study carried out in a tertiary hospital.
  
  
  METHODS
  We studied 100 singleton pregnant women with threatened preterm delivery and intact membranes, between 24 and 34 weeks, recruited during the period 2006-2008. A cervical swab for IL-6 detection was taken and a transvaginal ultrasound scan was performed for measuring the cervical length.
  
  
  RESULTS
  Five women delivered within 2 d and six women within 7 d. A high cervical IL-6 concentration was found in these women. The area under the ROC curve for cervical IL-6 was 0.97 for deliveries within 2 d after the test, and 0.85 for deliveries within 7 d. The optimal cut-off point was a cervical IL-6 concentration of 210 pg/ml. The negative predictive value (NPV) was 100% for deliveries within 2 d, and 98.5% for deliveries within 7 d (when considering a prevalence of preterm birth of 8%). Cervical IL-6 and sonographic measurement of cervical length showed similar NPV.
  
  
  CONCLUSIONS
  A low-cervical IL-6 concentration can accurately identify symptomatic women with a very low chance to progress to preterm birth within 2-7 d.
authors.affiliation: Department of Obstetrics, Hospital Universitario La Fe, Valencia, Spain.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Perales-Puchalt
authors.forename: Maia
authors.initials: M
authors.lastname: Brik
authors.forename: Vicente J
authors.initials: VJ
authors.lastname: Diago
authors.forename: Alfredo
authors.initials: A
authors.lastname: Perales
mesh_terms: D000328:Adult; D002582:Cervix Mucus / Q000737:chemistry* / Q000378:metabolism; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D015850:Interleukin-6 / Q000032:analysis* / Q000378:metabolism; D011237:Predictive Value of Tests; D011247:Pregnancy; D011262:Pregnancy Trimester, Second / Q000378:metabolism; D011263:Pregnancy Trimester, Third / Q000378:metabolism; D047928:Premature Birth / Q000175:diagnosis* / Q000453:epidemiology; D015995:Prevalence; D018570:Risk Assessment; D055815:Young Adult
chemical_list: D015850:Interleukin-6