Universal cervical‐length screening to prevent preterm birth in twin pregnancy: cost‐utility analysis

The purpose of this cost-utility analysis was to model the clinical and economic impact of three cervical-length screening strategies among low-risk twin pregnancies: two-step universal screening (at 18-20 and 20-22 weeks), one-step universal screening (at 18-20 weeks) and no screening. This study used a decision-analytic model (decision tree and cohort state transition model) with a 100-year time horizon in a Canadian context. The population included dichorionic diamniotic twin pregnancies without a history of preterm birth or prophylactic progesterone or cerclage. The model assumed that vaginal progesterone was initiated for cervical length ≤ 25 mm and that cervical cerclage was performed plus vaginal progesterone treatment for cervical length ≤ 15mm. The primary outcomes were total lifetime health-related costs (in 2023 Canadian dollars ($)), quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios. Clinical outcomes included the probability of preterm birth (≤ 28 and ≤ 34 weeks), probability of stillbirth and life expectancy. Probabilistic and deterministic sensitivity analyses were carried out. Base-case and probabilistic sensitivity analysis showed that, when compared with no screening, the two-step screening strategy increased the QALYs modestly (0.62 (95% credible interval (CrI), -0.16 to 1.41)) and decreased lifetime costs (-$2460 (95% CrI, -$4850 to $251)) by reducing the rate of preterm birth. The one-step screening strategy, although inferior to the two-step screening strategy, also increased the QALYs and reduced costs. Findings consistent with these were obtained on testing of the model assumptions with deterministic sensitivity analysis. This cost-utility analysis supports a universal two-step screening strategy for twin pregnancies in a Canadian context. Although the conclusions of this analysis are robust in terms of the sensitivity analysis, more reliable predictions of long-term costs and quality of life require more twin-specific lifetime data. Additionally, cost-utility analyses in other healthcare contexts are needed. © 2025 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.