To determine the most cost-effective gestational age of delivery for women undergoing inpatient management for monochorionic-monoamniotic (MCMA) twin gestations.METHODS:
A decision-analytic model was created comparing timing of delivery for MCMA pregnancies undergoing inpatient continuous fetal monitoring beginning at 26 weeks. Each arm of the tree represented a different gestational age at time of induction of labor, ranging from 28 to 34 weeks. Strategies involving expectant management accounted for probabilities of intrauterine fetal demise (IUFD) and spontaneous delivery at each successive week. Examined outcomes included quality adjusted life years (QALYs), IUFD, cerebral palsy and neonatal death. All probabilities, utilities, and costs were derived from the literature. The primary outcome was the incremental cost per QALY. The cost-effectiveness threshold was set at $100,000 per QALY. Univariate and multivariate analyses were used to investigate model robustness.RESULTS:
In a theoretical cohort of 250 MCMA twin pregnancies, delivery at 34 weeks would save $130 million compared to delivery at 28 weeks. Perinatal mortality was lowest at 30 weeks (12) and highest at 34 weeks (18). QALYs were highest at 31 week (21,146) and lowest at 28 weeks (20,799). Taken together, the most cost-effective strategy was delivery at 32 weeks gestation at $395 per QALY. Sensitivity analysis demonstrated that delivery at 32 weeks remained the optimal strategy until weekly cost of inpatient management was decreased to $4,038, at which point delivery at 33 weeks became the optimal strategy.CONCLUSION:
Delivering at 32 weeks gestation is the most cost-effective strategy for MCMA twin gestations undergoing continuous fetal monitoring.