title: High interleukin-16 concentrations in the early second trimester amniotic fluid: an independent predictive marker for preterm birth.
abstract: OBJECTIVE
  Infection is believed to be one of frequent and important causes of preterm labor. We attempted to evaluate whether the level of inflammatory markers, e.g. interleukin-16 (IL-16), interleukin-18 (IL-18), and ferritin, in amniotic fluid at early second trimester can predict preterm birth.
  
  
  METHODS
  Amniotic fluid (AF) samples were collected from 350 pregnant women who had trans-abdominal amniocentesis for genetic indications at 16 to 20 weeks of gestation. AF levels of IL-16, IL-18 and ferritin levels were measured by immunoassay and were correlated with pregnancy outcomes.
  
  
  RESULTS
  Among the 350 pregnant women, 58 (16.6%) had preterm birth (<37 weeks gestation). AF levels of IL-16, IL-18, and ferritin were significantly higher in pregnant women with subsequent preterm birth. Multivariate analyses showed that a quartile higher of AF IL-16 level was significantly associated with preterm birth (OR: 3.09, 95% CI 1.52-6.27, p = 0.002). A receiver operating characteristic analysis revealed that an IL-16 cutoff value of 105 pg/ml was a reliable predictor of preterm birth (sensitivity, 90.2%; specificity, 52.7%; negative predictive value, 84.3%).
  
  
  CONCLUSIONS
  It is feasible to predict preterm birth by measuring the AF levels of IL-16 especially for the pregnant women requiring genetic amniocentesis during early second trimester.
authors.affiliation: Department of Obstetrics and Gynecology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan. tyhsu@adm.cgmh.org.tw
authors.forename: Te-Yao
authors.initials: TY
authors.lastname: Hsu
authors.forename: Hao
authors.initials: H
authors.lastname: Lin
authors.forename: Kuo-Chung
authors.initials: KC
authors.lastname: Lan
authors.forename: Chia-Yu
authors.initials: CY
authors.lastname: Ou
authors.forename: Ching-Chang
authors.initials: CC
authors.lastname: Tsai
authors.forename: Bi-Hua
authors.initials: BH
authors.lastname: Cheng
authors.forename: Kuender D
authors.initials: KD
authors.lastname: Yang
authors.forename: Yi-Hsun
authors.initials: YH
authors.lastname: Wong
authors.forename: Tiao-Hsien
authors.initials: TH
authors.lastname: Hung
authors.forename: Pi-Yu
authors.initials: PY
authors.lastname: Hsiao
authors.forename: Hui-Fen
authors.initials: HF
authors.lastname: Kao
mesh_terms: D000328:Adult; D000649:Amniocentesis; D000653:Amniotic Fluid / Q000737:chemistry*; D015415:Biomarkers / Q000032:analysis; D005240:Feasibility Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D019410:Interleukin-16 / Q000032:analysis* / Q000378:metabolism*; D009994:Osmolar Concentration; D011247:Pregnancy; D011262:Pregnancy Trimester, Second / Q000378:metabolism*; D047928:Premature Birth / Q000175:diagnosis*; D011379:Prognosis
chemical_list: D015415:Biomarkers; D019410:Interleukin-16