title: The risks and benefits of internal monitors in laboring patients.
abstract: OBJECTIVE
  The purpose of this study was to estimate the impact of internal monitors (fetal scalp electrode [FSE] and intrauterine pressure catheter [IUPC]) on maternal and neonatal outcomes.
  
  
  METHODS
  The study comprised a retrospective cohort of all women who were admitted for labor from 2004-2008. Women with internal monitors (FSE, IUPC, or both) were compared with women without internal monitors. Maternal outcomes were maternal fever and cesarean delivery. Neonatal outcomes were a composite of 5-minute Apgar score of ≤3, cord pH <7.1, cord base excess ≤-12, or admission to level 3 nursery. Logistic regression was performed to estimate the impact of internal monitors with adjustment for confounding variables, including time in labor.
  
  
  RESULTS
  Of 6445 subjects, 3944 women (61.2%) had internal monitors. Women with internal monitors were more likely to have a fever than women without internal monitors (11.7% vs 4.5%; adjusted odds ratio [AOR], 2.0; 95% confidence interval [CI], 1.6-2.5). FSE alone was not associated with an increased risk of fever (AOR, 1.5; 95% CI, 1.0-2.1), but IUPC alone was (AOR, 2.4; 95% CI, 1.8-3.2). The risk of cesarean delivery was higher in women with internal monitors (18.6% vs 9.7%; AOR, 1.3; 95% CI, 1.0-1.5). Risk of cesarean delivery was lower in women with an FSE alone (AOR, 0.5; 95% CI, 0.4-0.7) but higher in women with both an FSE and an IUPC (AOR, 1.6; 95% CI, 1.4-2.0). Risk of the composite neonatal outcome was not higher in women with internal monitors (3.3% vs 3.6%; AOR, 0.8; 95% CI, 0.6-1.1).
  
  
  CONCLUSIONS
  Routine use of an IUPC in laboring patients should be avoided because of an increased risk of maternal fever.
authors.affiliation: Department of Obstetrics and Gynecology, University of Alabama, Birmingham, School of Medicine, Birmingham, AL.
authors.forename: Lorie M
authors.initials: LM
authors.lastname: Harper
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Shanks
authors.forename: Methodius G
authors.initials: MG
authors.lastname: Tuuli
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Roehl
authors.forename: Alison G
authors.initials: AG
authors.lastname: Cahill
mesh_terms: D000328:Adult; D001034:Apgar Score; D002585:Cesarean Section / Q000706:statistics & numerical data*; D005260:Female; D005323:Fetal Monitoring / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D005334:Fever / Q000209:etiology*; D006801:Humans; D007231:Infant, Newborn; D007743:Labor, Obstetric / Q000502:physiology*; D016015:Logistic Models; D008875:Middle Aged; D007744:Obstetric Labor Complications / Q000175:diagnosis / Q000209:etiology* / Q000382:microbiology; D016017:Odds Ratio; D011247:Pregnancy; D012189:Retrospective Studies; D018570:Risk Assessment; D013290:Streptococcal Infections / Q000209:etiology; D013292:Streptococcus agalactiae / Q000472:pathogenicity
keywords: cesarean delivery; chorioamnionitis; endometritis; internal monitor; labor
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