Abstract
Background Oxytocin is one of the most frequently used medications in obstetrics. It is generally
considered to be safe and effective for induction and augmentation of labor but has
been implicated in uterine hyperstimulation and adverse fetal outcomes. The management
of labor with oxytocin in response to changes in fetal status remains an area of debate.
Objective This study sought to assess the cost-effectiveness of reducing or ceasing oxytocin
administration in response to Category II fetal heart rate tracings.
Study Design A decision-analytic model was built using TreeAge 2016 software (TreeAge Software
Inc.) with probabilities, costs, and utilities derived from the literature. Primary
outcomes included cerebral palsy (CP), neonatal mortality, and mode of delivery. Secondary
outcomes included cost per quality-adjusted life year (QALY; cost-effectiveness threshold
set at $100,000/QALY), admission to the neonatal intensive care unit (NICU), and low
5-minute Apgar score (<7). Sensitivity analyses were performed to determine the robustness
of our baseline assumptions.
Results In a theoretical cohort of 900,000 women (estimated number of women undergoing induction
at term in the United States), decreasing or stopping oxytocin in response to Category
II tracings prevented 12,510 NICU admissions, 4,410 low Apgar scores, 204 neonatal
deaths, and 126 cases of CP. However, there were 81,900 more cesarean deliveries.
The strategy cost $356 million more, but was cost-effective with an ICER of $9,881.5
per QALY. Sensitivity analysis revealed that the intervention would be cost-effective
up to a cesarean rate of 54%.
Conclusion Decreasing or stopping oxytocin in response to Category II fetal heart rate tracings
is cost-effective. This intervention increases the rate of cesarean deliveries but
reduces neonatal morbidity and mortality. Further work on this guideline should be
performed to ascertain how the approach using different aspects of the Category II
tracing to guide care might lead to similar improved outcomes without increasing the
cesarean delivery rate.
Keywords
Category II tracing - cost-effectiveness - fetal heart rate monitoring - induction
- labor management - oxytocin
