BENIGN FEVER FOLLOWING VAGINAL DELIVERY

BACKGROUND. In patients with fever following vaginal delivery, physici ans must differentiate benign self-resolving fevers from fevers with m ore serious causes, especially endometritis. To help differentiate the se clinical entities, we explored the characteristics acid risk factor s for benign ''single-day'' postpartum fever. METHODS. We conducted a retrospective cohort study of 2137 vaginal deliveries. Patients were r andomly selected from the 25,687 vaginal deliveries that took place be tween 1979 and 1992 at The University of Iowa Hospitals and Clinics. T he data were analyzed using odds ratios and multiple logistic regressi on. RESULTS. Benign fevers occurred in 3.3% of patients, while endomet ritis was diagnosed in 1.6%. After controlling for confounding variabl es, two clinical factors were independently associated with single-day fever: primiparity (odds ratio [OR], 3.4; 95% confidence interval [CI ], 2.0 to 5.7) and use of a uterine pressure catheter (OR, 2.4; 95% Cl , 1.5 to 3.7). These factors were not associated with endometritis. Th e first postpartum temperature elevation (greater than or equal to 38. 0 degrees C) occurred earlier in patients with single-day fever than i n patients with endometritis (4.0 +/- 4.6 hours postpartum vs 30.2 +/- 27.0 hours postpartum, P < .001). The maximum temperature elevation w as lower, on average, in patients with single-day fever than in patien ts with endometritis (38.2 degrees +/- 0.2 degrees C vs 38.9 degrees /- 0.6 degrees C, P < .001). CONCLUSIONS. Single-day fever was more li kely to occur in primiparous women and in women who were monitored wit h a uterine pressure catheter. Most women with benign single-day fever s had early low-grade fevers, whereas women with endometritis had high er fevers that occurred later in the postpartum period.