Intrapartum fever at term: serum and histologic markers of inflammation

Am J Obstet Gynecol. 2003 Jan;188(1):269-74. doi: 10.1067/mob.2003.11.


Objective: This study was undertaken to determine whether intrapartum fevers at term are associated with markers of acute inflammation in maternal, fetal, and placental compartments.

Study design: Term cases with intrapartum fever (temperature >/=100.4 degrees F) were recruited with gestational age-matched controls. Maternal serum and umbilical vein blood were collected and assayed for interleukin-6 (IL-6) levels. Placentas were examined for histologic chorioamnionitis. Demographic and clinical data were collected and compared between cases and controls.

Results: Forty-seven case-control pairs were analyzed. Maternal IL-6 levels were higher in cases than in controls (median of 145 pg/mL vs 42 pg/mL, P <.0001). Umbilical vein IL-6 levels also were higher in cases than controls (median 9 pg/mL vs 3.5 pg/mL, P =.01), but more than half of levels in cases were below 11 pg/mL. Only 31.1% of febrile cases had moderate or severe histologic chorioamnionitis. Multivariable logistic regression identified maternal serum IL-6 levels, nulliparity, and number of vaginal examinations as the major predictors of intrapartum fever at term.

Conclusion: The maternal inflammatory response as measured by maternal serum IL-6 levels is a strong marker for term intrapartum fever. The much weaker association of fetal and placental inflammatory responses suggest a smaller than expected contribution of intra-amniotic inflammation to term intrapartum fevers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Case-Control Studies
  • Chorioamnionitis / blood
  • Chorioamnionitis / pathology
  • Continental Population Groups
  • Female
  • Fetal Blood / chemistry
  • Fetal Diseases
  • Fever*
  • Gestational Age
  • Humans
  • Inflammation / blood
  • Inflammation / diagnosis*
  • Inflammation / pathology
  • Interleukin-6 / blood
  • Labor, Obstetric*
  • Parity
  • Physical Examination
  • Placenta / pathology
  • Pregnancy
  • Prospective Studies
  • Regression Analysis
  • Risk Factors
  • Tachycardia
  • Umbilical Veins
  • Vagina


  • Interleukin-6