title: Placental inflammation and viral infection are implicated in second trimester pregnancy loss.
abstract: OBJECTIVE
  Second trimester pregnancy loss continues to be a poorly understood adverse obstetric outcome. A case control study was performed to determine if: (1) similar to early spontaneous preterm birth, second trimester loss is associated with histologic chorioamnionitis (HCA); and (2) if HCA is present, which organisms may mediate this placental inflammation.
  
  
  METHODS
  Cases were patients with a spontaneous second trimester loss. Controls were patients who presented for induction of labor for fetal or maternal indications. Nested polymerase chain reaction (PCR) was performed on placental tissues to detect the presence of viruses and pathogenic and atypical bacteria. Chi-square and Fisher exact test were used to determine if HCA and/or the presence of virus or bacteria were significantly associated with second trimester loss. The associations of interest were adjusted for possible confounders using multivariable logistic regression.
  
  
  RESULTS
  HCA was more prevalent in cases (67%) than controls (16%) (P < .001). Seventy-nine percent (66/84) of cases and 44% (7/16) of controls were positive for any virus (P = .01). The rate of bacterial infection was similar in both cases and controls (P = .35). In multivariable logistic regression models, HCA (odds ratio [OR] 14.58, 2.62-81.15) and the presence of any virus (OR 6.62, 1.56-28.07) were independently associated with second trimester loss.
  
  
  CONCLUSIONS
  These studies demonstrate that spontaneous second trimester loss is strongly associated with HCA and viral infections.
authors.affiliation: Department of Obstetrics and Gynecology, University of Pennsylvania Health System, Philadelphia, PA, USA. ssrinivas@obgyn.upenn.edu
authors.forename: Sindhu K
authors.initials: SK
authors.lastname: Srinivas
authors.forename: Yujie
authors.initials: Y
authors.lastname: Ma
authors.forename: Mary D
authors.initials: MD
authors.lastname: Sammel
authors.forename: Doris
authors.initials: D
authors.lastname: Chou
authors.forename: Cindy
authors.initials: C
authors.lastname: McGrath
authors.forename: Samuel
authors.initials: S
authors.lastname: Parry
authors.forename: Michal A
authors.initials: MA
authors.lastname: Elovitz
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology / Q000382:microbiology / Q000473:pathology* / Q000821:virology*; D000328:Adult; D016022:Case-Control Studies; D002821:Chorioamnionitis / Q000453:epidemiology / Q000473:pathology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D016015:Logistic Models; D010920:Placenta / Q000473:pathology* / Q000821:virology*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology*; D011262:Pregnancy Trimester, Second; D011446:Prospective Studies