Modelling the cost-effectiveness of early term induction of labour to prevent shoulder dystocia for fetuses suspected to be large for gestational age and/or macrosomic (Big Baby 3)

Research Question: What is the cost-effectiveness of early term induction of labour (IOL) at 38 weeks gestation for fetuses suspected to be large-for-gestational-age (LGA) and/or macrosomic compared to standard care or planned caesarean section? Background: Shoulder dystocia, when the fetal shoulder is trapped behind the mother s pubic bone, requiring additional obstetric manoeuvres to deliver the fetus, occurs in 2–5% of cephalic vaginal births. This increases the risk of maternal complications and neonatal morbidity and mortality. It is more common in LGA (generally defined as >90th birthweight centile) and/or macrosomic (birthweight >4kg) pregnancies; henceforth, LGA will refer to LGA and/or macrosomia in this proposal. The Big Baby Trial found a non-significant reduction in shoulder dystocia in IOL at 38 weeks gestation but was associated with increased short-term neonatal care costs. The Big Baby 2UP study is assessing two-year neurodevelopmental outcomes, but the long-term cost-effectiveness of early term IOL for LGA remains unknown. Aims and Objectives: Our overarching aim to generate rigorous evidence to help clinicians, policymakers, and pregnant women make informed decisions about early term IOL for suspected LGA fetuses. Our objectives are to; find out what is known about the cost-effectiveness of different delivery strategies for suspected LGA pregnancies estimate essential data needed to inform the economic model that are not available from the literature model the comparative cost-effectiveness of early term IOL for suspected LGA pregnancies. Methods: Building on our previous studies we propose three work packages (WPs): WP1: A systematic review of economic evaluations comparing early term induction, standard care, and planned caesarean for suspected LGA fetuses will assess maternal and neonatal outcomes, healthcare resource use and cost-effectiveness. Studies will be appraised using the CHEERS and Phillips et al. tools, with findings synthesised to inform the economic model. WP2: A structured expert elicitation panel of healthcare professionals and patient representatives will address uncertainties by estimating clinical outcomes, healthcare resource use, and long-term effects of early term induction not obtained from WP1. WP3: An economic model will estimate the long-term cost-effectiveness of early term IOL from an NHS and Personal Social Services perspective, using a lifetime horizon. Outcomes will be measured in quality-adjusted life years (QALYs) and cost-effectiveness in terms of cost per QALY gained, with results presented as cost-effectiveness acceptability curves to quantify uncertainty. Patient and Public Involvement: Working with two PPI representatives, we will ensure patient involvement throughout the study. They will contribute via regular discussions, providing input on study design, model parameters, result interpretation, and dissemination. Their insights will refine model assumptions and ensure findings are accessible to parents and patient communities. Timelines for Delivery: The project will be completed in 14 months. Anticipated Impact and Dissemination: The findings will provide insights into the cost-effectiveness of early term IOL for LGA pregnancies, informing clinical guidelines. Results will be published in peer-reviewed journals and presented at conferences. In collaboration with the Erb s Palsy Group, we will develop lay summaries and use a dedicated project webpage and social media to ensure broad dissemination.