Intrapartum fever at term: clinical characteristics and placental pathology

To investigate the association between clinical characteristics and placental histopathology in women with intrapartum fever (IPF) at term.

Maternal characteristics, intrapartum parameters, neonatal outcome and placental pathology were compared between 120 patients with IPF (≥ 380C) and a control group matched for mode of delivery. Placental lesions were classified as consistent with maternal circulation abnormalities or fetal thrombo-occlusive disease or inflammatory responses of maternal (MIR) or fetal (FIR) origin.

Compared to controls the study group was characterized by significantly higher rates of nulliparity, extra-amniotic balloon induction of labor, and epidural anesthesia, higher gestational age, higher white blood cell count, and more vaginal examinations. On multivariate logistic regression analysis, multiple vaginal examinations were independently associated with IPF. MIR was detected in 71% of the study group compared to 21% of controls (p < 0.001), and FIR, in 32.5% and 7.5%, respectively (p < 0.001). IPF was independently associated with inflammation of maternal origin (adjusted odds ratio (OR) 8.0, 95% CI 4.2-15.2, p < 0.001) and fetal origin (adjusted OR 5.2, 95% CI 2.07-13.4, p < 0.001). Neonatal outcome was similar in the two groups.

Multiple vaginal examinations are a significant risk factor for the development of IPF. IPF at term is independently associated with placental inflammatory lesions.