title: Maternal serum levels of interleukin-6 and clinical characteristics of normal delivery at term.
abstract: BACKGROUND
  The objective of the present study was to study participation of cytokines and cytokine inhibitors during the process of normal parturition, as assessed by maternal serum levels of interleukin-1 (IL-1), interleukin-6 (IL-6), tumor necrosis factor (TNF) and soluble tumor necrosis factor receptors (sTNFRs, p55 and p75).
  
  
  METHODS
  Twenty-six healthy women in normal term labor were observed during parturition and until 2 h post partum. Serum was sampled every 2 h, and an evaluation of strength and frequency of contractions was performed at the time of sampling. Concentrations of IL-1, IL-6, TNF, p55 and p75 were analyzed, and non-parametric tests were used to study whether any relationship existed between the serum analyzes and the clinical characteristics of parturition.
  
  
  RESULTS
  There was a significant association between the strength of contractions and the levels of IL-6 and p55. In addition, IL-6 concentrations and frequency of contractions were correlated. Maternal serum levels of IL-6 and p55 were highest 2 h post partum. TNF activity was detected in samples from nine women, whereas IL-1 was not found in any sample.
  
  
  CONCLUSIONS
  The present study suggests a role of IL-6 and p55 in normal labor. However, as women being studied already were in labor, the study does not allow any conclusions whether observed changes in IL-6 and p55 levels have a causal relation to the process of labor or if changes are secondary effects of the process itself.
authors.affiliation: Institute of Cancer Research and Molecular Biology, University Medical Center, Trondheim, Norway.
authors.forename: K J
authors.initials: KJ
authors.lastname: Arntzen
authors.forename: E
authors.initials: E
authors.lastname: Lien
authors.forename: R
authors.initials: R
authors.lastname: Austgulen
mesh_terms: D000328:Adult; D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000097:blood; D016207:Cytokines / Q000097:blood*; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D007743:Labor, Obstetric / Q000097:blood*; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000097:blood; D018124:Receptors, Tumor Necrosis Factor / Q000097:blood; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D016207:Cytokines; D007375:Interleukin-1; D015850:Interleukin-6; C097324:P55-L5 protein, Borrelia burgdorferi; D011257:Pregnancy Proteins; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha