title: Clinical significance of histologic chorioamnionitis with a negative amniotic fluid culture in patients with preterm labor and premature membrane rupture.
abstract: OBJECTIVE
  To evaluate the effect of histological chorioamnionitis (HCA) with a negative amniotic fluid (AF) culture on adverse pregnancy and neonatal outcomes and inflammatory status in the AF compartment in women with preterm labor or preterm premature rupture of membranes (PPROM).
  
  
  METHODS
  This is a retrospective cohort study of 153 women diagnosed as having a preterm labor or PPROM (20-34 weeks) who delivered singleton gestations within 48 hours of amniocentesis. AF obtained through amniocentesis was cultured, and interleukin (IL)-6, IL-8, and metalloproteinase-9 (MMP-9) levels were determined. The placentas were examined histologically.
  
  
  RESULTS
  The prevalence of HCA with negative AF culture was 23.5% (36/153). The women with HCA but with a negative AF culture (group 2) and those with a positive AF culture (group 3) had a significantly lower mean gestational age at amniocentesis and delivery than those with a negative AF culture and without HCA (group 1). Women in group 3 had the highest levels of AF IL-6, IL-8, and MMP-9, followed by those in group 2, and those in group 1. Composite neonatal morbidity was significantly higher in groups 2 and 3 than in group 1, but this was no longer significant after adjusting for confounders caused mainly by the impact of gestational age.
  
  
  CONCLUSIONS
  In the women who delivered preterm neonates, HCA with a negative AF culture was associated with increased risks of preterm birth, intense intra-amniotic inflammatory response, and prematurity-associated composite neonatal morbidity, and its risks are similar to the risk posed by positive AF culture.
authors.affiliation: Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea.|Department of Obstetrics and Gynecology, Inje University College of Medicine, Ilsan-Paik Hospital, Gyeonggi, Korea.
authors.forename: Jeong Woo
authors.initials: JW
authors.lastname: Park
authors.affiliation: Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea.|Department of Obstetrics and Gynecology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Kyo Hoon
authors.initials: KH
authors.lastname: Park
authors.affiliation: Department of Obstetrics and Gynecology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Jung
mesh_terms: D000328:Adult; D000653:Amniotic Fluid / Q000378:metabolism; D002821:Chorioamnionitis / Q000473:pathology*; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000378:metabolism*; D006801:Humans; D007231:Infant, Newborn; D007752:Obstetric Labor, Premature / Q000378:metabolism*; D011247:Pregnancy; D012189:Retrospective Studies