Objective Cervical Stiffness Assessment Using the Pregnolia System Prior to Induction of Labour: The CASPAR...

To determine if the Pregnolia System (PS) for cervical stiffness (CS) assessment is feasible for an induction of labour (IOL) cohort and to inform definitive study design for IOL outcome prediction.

Single-centre, prospective, observational, feasibility study.

Liverpool Women's Hospital (Liverpool, UK) IOL suite.

100 nulliparous, term pregnant women with intact membranes undergoing IOL.

Participants underwent a CS assessment using the PS and routine Bishop Score (BS) before IOL commenced. Participants completed an acceptability questionnaire. Decision for IOL was as per clinical team and unit policy. Clinical outcomes were collected from electronic records after delivery.

Feasibility outcomes; recruitment rate, acceptability profile and assessment tool fidelity in this cohort. Clinical outcomes; exploring associations between Pregnolia System CS results and IOL outcomes of interest.

Recruitment was good at 68% (100/148). Reliability analysis of completed CS assessments showed internal consistency to be excellent (Cronbach's Alpha 0.967). The PS assessment had a lower discomfort score compared to Bishop Score assessment (mean difference 3.73). Exploratory clinical outcome analysis revealed both cervical assessment tools had poor diagnostic capability for vaginal delivery following IOL (PS AUC 0.466 95% CI 0.340, 0.593, BS AUC 0.621 95% CI 0.497-0.745).

This novel study confirms the feasibility of the PS for pre-induction cervical assessment. However, it could not determine the clinical utility in this cohort due to the study design for feasibility outcomes.