title: Evaluation of effectiveness of prophylactic cerclage of a short cervix according to interleukin-8 in cervical mucus.
abstract: OBJECTIVE
  This study was undertaken to compare rates of preterm delivery according to cervical mucus interleukin-8 (IL-8) among women who underwent cerclage because of a short cervix.
  
  
  METHODS
  This retrospective study included 16,508 patients whose cervical length and cervical mucus IL-8 concentrations were measured between 20 and 24 weeks. A short cervix was defined by a length of 25 mm or less, whereas IL-8 concentrations exceeding 360 ng/mL were considered high. Whether to perform cerclage was decided by clinicians without consideration of IL-8 concentrations.
  
  
  RESULTS
  Among all subjects, a significantly smaller percentage of subjects avoided delivery before 37 weeks when cervical mucus IL-8 was elevated (P = .0302) or the cervix was short (P < .0001). Among patients with a short cervix, preterm delivery was more likely when cervical mucus IL-8 was elevated. Overall, risk of preterm delivery in patients with a short cervix did not differ between those undergoing and not undergoing cerclage. However, among patients with a short cervix, those with normal IL-8 concentrations in cervical mucus were less likely to have preterm delivery if they underwent cerclage (before 37 weeks, 33% vs 54.5%, P = .01; before 34 weeks, 4% vs 13.6%, P = .03). In contrast, when cervical mucus IL-8 was high, delivery before 37 weeks was more likely with than without cerclage (78% vs 54.1%, P = .03).
  
  
  CONCLUSIONS
  With normal cervical mucus IL-8, cerclage treatment for cervical shortening may reduce the rate of preterm delivery, but with elevated cervical mucus IL-8 cerclage may be harmful.
authors.affiliation: Department of Obstetrics, Toyama Medical and Pharmaceutical University, Toyama, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Sakai
authors.forename: Arihiro
authors.initials: A
authors.lastname: Shiozaki
authors.forename: Mika
authors.initials: M
authors.lastname: Tabata
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yoneda
authors.forename: Takashi
authors.initials: T
authors.lastname: Arai
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kato
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Yamakawa
authors.forename: Shigeru
authors.initials: S
authors.lastname: Saito
mesh_terms: D023802:Cerclage, Cervical / Q000009:adverse effects; D002582:Cervix Mucus / Q000737:chemistry*; D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D016209:Interleukin-8 / Q000032:analysis*; D009929:Organ Size; D009994:Osmolar Concentration; D011247:Pregnancy; D047928:Premature Birth / Q000517:prevention & control*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014463:Ultrasonography; D002581:Uterine Cervical Incompetence / Q000000981:diagnostic imaging / Q000601:surgery*
chemical_list: D016209:Interleukin-8