OBJECTIVES: The US has a higher preterm birth (PTB) rate than other developed nations, despite the availability of screening and preventive treatments. Short cervix (SC), cervical length (CL) <25mm on transvaginal sonography, is a common risk factor for PTB (delivery <37 gestational weeks). SC is diagnosed through serial CL screening (SS); three treatments are available to those diagnosed with SC. Objective was to develop a decision analytic model to assess costs and effectiveness of SS versus no screening (NS) in preventing PTB among high-risk US women (those with history of PTB) carrying a singleton gestation.

METHODS: Decision analytic model was constructed to compare SS to NS from the US healthcare payer perspective in $US 2016. Assumptions include: 1) SS initiated at gestational week 16 (average 2-3 ultrasounds); 2) subtree assessed least costly treatment option (cerclage, vaginal progesterone, pessary) for SC; 3) women without SC received intramuscular hydroxyprogesterone (17-OHP) weekly until delivery or 36 weeks; 4) women in NS received weekly 17-OHP until delivery or 36 weeks. Costs included procedures (CL screening, cerclage, pessary), medications (17-OHP, vaginal progesterone), and direct healthcare costs of delivery plus maternal and neonatal costs for one year post-delivery. Effectiveness threshold was delivery ≥37weeks. Main outcome was difference in cost and effectiveness between SS and NS.

RESULTS: Total SS cost was $45,907, with pessary dominating in the SC subtree, versus $54,953. Similar effectiveness was observed between SS and NS (0.65 vs. 0.64 PTB prevented, respectively). SS yielded net savings of $9,046 versus NS.

CONCLUSIONS: For women with SC, SS plus pessary is predicted to be cost-saving compared to NS in preventing recurrent PTB. This model is critical to informing US practice and policy because it employs current options to prevent PTB in high-risk women with SC. Future work includes refining model to include new pessary efficacy data.