title: Evaluation of amniotic fluid cytokines in preterm labor and intact membranes.
abstract: OBJECTIVE
  To compare the amniotic fluid (AF) concentration of pro-inflammatory cytokines between women with preterm labor and intact membranes that delivered within 7 days, with those that delivered after 7 days of the amniocentesis according to the result of the AF culture.
  
  
  METHODS
  Fifty-two women with preterm labor and intact membranes between 21 and 35 weeks of gestation were included in the study. Transabdominal amniocentesis was performed to rule out intra-amniotic infection, and AF concentrations of interleukin-1alpha (IL-1alpha), interleukin-1beta (IL-1beta), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor (TNF) were determined with sensitive and specific enzyme-linked immunosorbent assays. Amniotic fluid was cultured for aerobic and anaerobic bacteria, Ureaplasma urealyticum, and Mycoplasma hominis. Exclusion criteria included preterm premature rupture of membranes, vaginal bleeding, multiple gestations, uterine anomalies, fetal congenital anomalies, ominous fetal heart rate tracings and fetal deaths. Proportions were compared using chi2 or Fisher's exact test. Receiver operator characteristic (ROC) curve analysis was performed for each cytokine for the prediction of delivery within 7 days.
  
  
  RESULTS
  Sixty-two percent (32/52) of women delivered within 7 days and 38% (20/52) delivered after 7 days of amniocentesis. All women that delivered after 7 days of the procedure had negative AF cultures. In contrast, 28% (9/32) of women that delivered within 7 days had positive AF cultures and 72% (23/32) had negative AF cultures. Women that delivered within 7 days regardless of AF cultures had a lower birth weight and a shorter amniocentesis-to-delivery interval than those that delivered after 7 days of amniocentesis. Among women that delivered within 7 days, those with positive AF cultures had a lower gestational age at delivery and a higher frequency of histologic chorioamnionitis than those with negative AF cultures. The AF concentrations of all cytokines were significantly higher in women that delivered within 7 days with positive AF cultures than in those with negative AF cultures. Similarly, the AF concentrations of IL-1alpha, IL-6, and IL-8 were significantly higher in women that delivered within 7 days than those that delivered after 7 days of the amniocentesis, regardless of the AF culture results. Diagnostic indexes were calculated for all cytokines using critical values derived from ROC curve analysis for the prediction of delivery within 7 days.
  
  
  CONCLUSIONS
  Women with preterm labor and intact membranes that delivered within 7 days had higher AF concentrations of pro-inflammatory cytokines than those who delivered after 7 days of the amniocentesis regardless of the AF culture results.
authors.affiliation: Department of Obstetrics, Cell Biology and Anatomy, New York Medical College, Valhalla, NY 11501, USA. rfigueroa@winthrop.org
authors.forename: Reinaldo
authors.initials: R
authors.lastname: Figueroa
authors.forename: David
authors.initials: D
authors.lastname: Garry
authors.forename: Andrew
authors.initials: A
authors.lastname: Elimian
authors.forename: Kirit
authors.initials: K
authors.lastname: Patel
authors.forename: Pravin B
authors.initials: PB
authors.lastname: Sehgal
authors.forename: Nergesh
authors.initials: N
authors.lastname: Tejani
mesh_terms: D000649:Amniocentesis; D000653:Amniotic Fluid / Q000378:metabolism* / Q000382:microbiology; D001724:Birth Weight; D002175:Candida / Q000302:isolation & purification; D002821:Chorioamnionitis / Q000382:microbiology; D005260:Female; D005865:Gestational Age; D006090:Gram-Negative Bacteria / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000302:isolation & purification; D006801:Humans; D007378:Interleukins / Q000378:metabolism*; D007752:Obstetric Labor, Premature / Q000276:immunology*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000382:microbiology; D012680:Sensitivity and Specificity; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D007378:Interleukins; D014409:Tumor Necrosis Factor-alpha