(880) Treating women with isolated intrapartum fever as chorioamnionitis: A cost effectiveness analysis

Objective: Intrapartum fever (≥ 38°C) affects many deliveries annually in the U.S., posing risks to mothers and neonates. Standard treatments include expectant management for isolated intrapartum fever and ampicillin-gentamicin for chorioamnionitis. Antibiotic treatment helps reduce infection risk due to expectant management but may increase costs. This study evaluated the cost-effectiveness of treating isolated intrapartum fever as chorioamnionitis.

Study Design: We constructed a decision-analytic model in TreeAge Pro to compare outcomes between isolated intrapartum fever (expectant management) versus chorioamnionitis (ampicillin/gentamicin). Our theoretical cohort was 222,000 patients, representing vaginal singleton pregnancies with intrapartum temperature ≥ 38°C in the U.S. annually. Outcomes were incremental cost per quality-adjusted life years (QALYs), postpartum endometritis, neonatal early-onset sepsis (nEOS), neonatal death, neonatal neurodevelopmental delay (NDD), and acute kidney injury (AKI) from gentamicin toxicity. The willingness-to-pay threshold was $100,000/QALY. We discounted QALYs at a rate of 3%. Model inputs were derived from literature and assessed using univariate sensitivity analyses.

Results: In our theoretical cohort of 222,000 individuals, antibiotic treatment reduced 7,481 cases of postpartum endometritis (8,649 vs 16,131), 6,047 cases of nEOS (961 vs 7,009), 677 neonatal deaths (1,350 vs 2,027), and 331 cases of NDD (15,485 vs 15,815) compared to expectant management. However, gentamicin use for chorioamnionitis resulted in 21,305 more cases of AKI (31,069 vs 9,764). Despite higher costs, treating intrapartum fever as chorioamnionitis was cost-effective with a cost-effectiveness ratio (ICER) of $5,708/QALY. Sensitivity analyses showed treatment remained cost-effective until AKI probability exceeded 70%.

Conclusion: Treating intrapartum fever with antibiotics is a cost-effective strategy to reduce the adverse outcomes of untreated intrapartum fever. Adopting a protocol to treat all intrapartum fevers ≥ 38°C as chorioamnionitis with appropriate antibiotics could benefit health systems.