title: Idiopathic vaginal bleeding during pregnancy as the only clinical manifestation of intrauterine infection.
abstract: OBJECTIVE
  To determine the frequency and clinical significance of microbial invasion of the amniotic cavity (MIAC) in patients with vaginal bleeding in the absence of placenta previa, preterm labor or preterm premature rupture of membranes (PROM).
  
  
  METHODS
  This retrospective cohort study included patients who presented with vaginal bleeding between 18 and 35 weeks, and underwent an amniocentesis shortly after admission for the assessment of the microbiologic status of the amniotic cavity and/or fetal lung maturity. Amniotic fluid was cultured for aerobic and anaerobic bacteria, as well as genital mycoplasmas. Patients presenting with preterm labor, preterm PROM, placenta previa, overt placental abruption, and an intrauterine device in situ were excluded, as well as those with local cervical bleeding. MIAC was defined as a positive amniotic fluid culture. Analysis was conducted with non-parametric statistics.
  
  
  RESULTS
  One hundred and fourteen patients met the entry criteria. MIAC was detected in 14% of cases (16/114). Patients with vaginal bleeding and a gestational age < 28 weeks at the time of amniocentesis had a significantly higher frequency of MIAC than those with a gestational age 28 weeks [25% (13/52) vs. 4.8% (3/62), respectively; p < 0.01]. Ureaplasma urealyticum was the microorganism most frequently isolated from the amniotic fluid. Except for one case admitted at 33 weeks, all patients with MIAC had an early preterm delivery 32 weeks. Patients with vaginal bleeding and MIAC had a shorter procedure-to-delivery interval than those without MIAC [MIAC, median survival 19 days (95% CI 10-27 days) vs. no MIAC, median survival 50 days (95% CI 37-62 days); p < 0.0001]. Patients with vaginal bleeding and MIAC had a significantly lower gestational age at delivery and lower birth weight than those with vaginal bleeding and negative amniotic fluid cultures (for gestational age, median 25 weeks, range 21-33 weeks vs. median 37 weeks, range 19-42 weeks, respectively; p < 0.01, and for birth weight, median 750 grams, range 520-1820 grams vs. 2800 grams, range 520-4880 grams, respectively; p < 0.01), as well as a higher frequency of subsequent preterm PROM [81.3% (13/16) vs. 9.2% (9/98); p < 0.01].
  
  
  CONCLUSIONS
  MIAC was detected in 14% of patients with 'idiopathic' vaginal bleeding and was associated with subsequent preterm PROM and early preterm delivery. Vaginal bleeding may be the only clinical manifestation of MIAC, and it predisposes to adverse outcome.
authors.affiliation: Center for Perinatal Diagnosis and Research (CEDIP), Sótero del Río Hospital, P. Universidad Católica de Chile, Puente Alto, Chile.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Gómez
authors.forename: Roberto
authors.initials: R
authors.lastname: Romero
authors.forename: Jyh Kae
authors.initials: JK
authors.lastname: Nien
authors.forename: Luis
authors.initials: L
authors.lastname: Medina
authors.forename: Mario
authors.initials: M
authors.lastname: Carstens
authors.forename: Yeon Mee
authors.initials: YM
authors.lastname: Kim
authors.forename: Tinnakorn
authors.initials: T
authors.lastname: Chaiworapongsa
authors.forename: Jimmy
authors.initials: J
authors.lastname: Espinoza
authors.forename: Rogelio
authors.initials: R
authors.lastname: González
mesh_terms: D000328:Adult; D000653:Amniotic Fluid / Q000382:microbiology*; D001424:Bacterial Infections / Q000150:complications*; D002821:Chorioamnionitis / Q000209:etiology; D015331:Cohort Studies; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000382:microbiology; D006801:Humans; D007752:Obstetric Labor, Premature / Q000209:etiology*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious; D011256:Pregnancy Outcome; D047928:Premature Birth; D012189:Retrospective Studies; D016990:Ureaplasma urealyticum / Q000302:isolation & purification; D014592:Uterine Hemorrhage / Q000209:etiology*